Real Madrid and Paris St-Germain are monitoring William Saliba's situation at Arsenal, with talks continuing over a new contract for the defender. (CaughtOffside), external
Want more transfer stories? Read Wednesday's full gossip column
Image source, Getty ImagesArsenal manager Mikel Arteta, speaking after Tuesday's 2-0 win against Athletic Club in the Champions League:
"I know how much these players want to play this competition and what it means to them, and every time you name the line-up, you are disappointing a lot of players.
"They know how I feel about them, so they know that when I have to leave a player on the bench or out of the squad, it hurts me.
"But to have that experience, I looked on the bench, I looked at Martinelli and in his eyes I could see that he was ready, Leo [Trossard] as well.
"I was sure that he [Martinelli] was going to react like that. He has such a mentality. He's a player that is constantly willing to learn and he proved himself. He is very demanding with himself.
"And that's the moment that hopefully is going to give him the confidence again to go, because he's an outstanding player and I am so happy he decided the game with his two actions."
Did you know?
Arsenal have become the first ever team to win six consecutive European Cup/UEFA Champions League matches against Spanish opponents.
Gabriel Martinelli opened the scoring for Arsenal just 36 seconds after coming off the bench - the Gunners' fastest ever goal by a substitute in the Champions League.
Alex Howell
Football reporter at San Mames, Bilbao
Image source, Getty ImagesGabriel Martinelli has been aware of the criticism and debate from fans about his place in the Arsenal team, but the two moments of play that led to the Gunners' two goals against Athletic Club showed why Mikel Arteta has kept faith with the 24-year-old.
Arteta knows he can trust him in the big games, but his attacking output had dropped as his confidence left him.
The winger is one of the fastest in the Premier League and Leandro Trossard's pass showed just how dangerous Martinelli can be when he gets the ball in the right areas of the pitch.
Arteta has previously said that he needed a bigger squad as the standards have raised, and because of the high number of games his players have to play throughout the season.
The Arsenal manager named five of his eight new summer signings in the starting XI and was able to introduce quality from the bench, something that was lacking last season as injuries hit his squad.
Trossard is never happy to be on the bench but Arteta will be delighted to have players of his and Martinelli's ability to turn to when he wants to impact games.
The high spend this summer will undoubtedly bring pressure to Arteta, but the manager can point to this game and show that being so aggressive in the transfer market was justified.
Image source, Getty ImagesFormer England goalkeeper Paul Robinson, speaking on BBC Radio 5 Live after Arsenal's 2-0 win against Athletic Club in Bilbao:
"Arsenal have done really well in the latter part of the second half. It has been a very good away performance and a good start to the Champions League.
"Let's not underestimate the job that they've done. They played against the team with the best defensive record in La Liga last season. They were always going to be a hard team to beat at home.
"The first half wasn't pretty but Arsenal dug in. The changes that they've made and the signings that they've made in the final third made the difference.
"Noni Madueke was excellent for the whole time down the right-hand side. Eberechi Eze never really got in the game and that forced the manager's hand. The substitutes came on and it was perfect timing as the game opened up for them.
"A really good start to the season for Arsenal."
Goals from substitutes Gabriel Martinelli and Leandro Trossard gave Arsenal a perfect start to their Champions League campaign in Bilbao.
Whether you were at the game or following from elsewhere, we want to know what you learned.
Get in touch with your views here
Come back to this page on Wednesday to find a selection of your replies
Arsenal boss Mikel Arteta makes just one change from the side that beat Nottingham Forest, as Declan Rice comes in for Martin Odegaard.
There's also a boost as William Saliba is fit enough to be on the bench.
Arsenal XI: Raya, Timber, Mosquera, Gabriel, Calafiori, Zubimendi, Rice, Merino, Madueke, Eze, Gyokeres.
Subs: Arrizabalaga, Setford, Saliba, Hincapie, Martinelli, Norgaard, Trossard, Nwaneri, Lewis-Skelly, Dowman.
Athletic Club XI: Unai Simon, Gorosabel, Vivian, Paredes, Adama, Vesga, Jauregizar, Williams, O Sancet, Navarro, Berenguer.
Subs: M Santos, Padilla, Guruzeta, Areso, Lekue, Galarreta, Yuri, Unai G, Maroan, Nico Serrano, Regi, Jon De Luis.
There are six games in the Champions League on Tuesday, two of them involving Premier League teams, and BBC Sport will bring you every moment.
Athletic Bilbao v Arsenal (17:45) - listen on BBC Radio 5 Live
PSV Eindhoven v Union Saint-Gilloise (17:45)
Benfica v Qarabag
Juventus v Borussia Dortmund
Real Madrid v Marseille
Tottenham v Villarreal - listen on BBC Radio 5 Live
Kick-off times 20:00 BST unless stated
Follow all of the action and reaction here
You can also listen to today's Radio 5 Live Champions League commentaries on most smart speakers. Just say "ask BBC Sounds to play Athletic Bilbao v Arsenal" or "ask BBC Sounds to play Tottenham v Villarreal".
There will also be a Champions League Match of the Day on BBC One on Wednesday, from 22:40 to 00:00.
Image source, Getty Images
Chief football writer Phil McNulty has been answering your questions.
Yemi asked: if you had to label one of the English teams as a dark horse - that could surprise everyone beyond that of the favourites Liverpool - which team would it be and for what reason?
Phil answered: I would say Arsenal because they reached the semi-finals last season and have added some real quality in the transfer window.
The experience of the last Champions League campaign will serve them well and they now have the strength of squad to finally break through and win one of the major trophies.
Do I think Arsenal will win the Champions League? Not so sure about that, but I think they can make a real impact.
Follow Phil's Q&A and the rest of the day's football news on our daily live page
Watch BBC Radio 5 Live's Monday Night Club panel discuss Arsenal and the recent impressive performances by new signing Noni Madueke.
"He was really refreshing," said former Newcastle goalkeeper Shay Given.
"The biggest thing is he had end product to most things. I'm actually surprised Chelsea let him go."
"There was a negativity around Madueke's signing," added The Observer's Rory Smith.
"I wonder to what extent it was because at that point Arsenal fans just wanted to sign a striker.
"If they had signed Viktor Gyokeres first I wonder if the reaction would have been different."
Watch the full episode on BBC iPlayer and listen on BBC Sounds
Laura Kirk-Francis
Fan writer
Image source, Getty ImagesMartin Zubimendi's arrival at Arsenal in July was perhaps not accompanied by the fanfare it deserved. The transfer was rumoured to have been agreed at the start of the year, so the signing of the Spaniard always seemed like a formality rather than an exciting surprise.
Before his display against Nottingham Forest, Zubimendi had enjoyed an encouraging start to the season. But it was his double on Saturday that really announced himself to the Premier League.
His first was simply a moment of magic, the exact type that Arsenal were undone by at Anfield in August.
In the first three weeks of the season, Arsenal had created the second-lowest xG in open play in the league. But on Saturday, chances were flowing and Zubimendi's effort showcased the exact technical brilliance that highlighted why Mikel Arteta was so keen to bring him to the club.
You cannot overstate the difficulty of the volley that sailed past goalkeeper Matz Sels. For many others, it would have simply rocketed over the crossbar.
The Spaniard rounded off his day with a header at the back post which sealed the game. Certainly not the tallest of Arsenal players, this is another string to Zubimendi's bow that make him one of the most versatile players this season.
When Arsenal announced the signing, their video sought to showcase his ability to control the tempo of games, knowing when to speed things up and slow things down. The video shows the player speaking over a drumbeat and a metronome.
Saturday was a perfect example of Zubimendi's ability to dictate play from the heart of midfield. Add in his two goals and he is doing exactly what Arsenal need him to do and more.
Find more from Laura Kirk-Francis at the Latte Firm podcast, external
Image source, Getty ImagesOpta's supercomputer has Arsenal as second favourites to win this season's Champions League.
The model estimates the probability of each match outcome (win, draw or loss) by using betting market odds and Opta's own power rankings. Both these areas are based on historical and recent team performances and the computer runs 10,000 simulations to create its predictions.
Having reached the semi-finals last time out, Mikel Arteta's side win the tournament in 18% of simulations, suggesting another strong campaign for the Gunners.
Image source, OptaThe Gunners have the second-easiest draw according to Opta's power rankings, with only Copenhagen ranked to have a 'easier' league phase.
Therefore, the supercomputer has Arsenal reaching the quarter-finals in 68% of simulations, matching last season's run 44.8% of the time and going one step further to the final more than a quarter of the time.
Having played the most European Cup/Uefa Champions League games without ever lifting the trophy (211), they will be hoping to change that this time.
Opta ranks the likeliest threats to Arsenal as favourites Liverpool (20.4%), and PSG (12.1%).
Scouts from Arsenal, Chelsea, Manchester United, Barcelona and Real Madrid have all been watching Ajax's 17-year-old Belgian midfielder Jorthy Mokio. (Caughtoffside), external
Want more transfer stories? Read Tuesday's full gossip column
Alex Howell
Arsenal reporter in Bilbao
Image source, AFP via Getty ImagesMikel Arteta has said he is excited to "start from scratch" as Arsenal prepare to play Athletic Bilbao in their first Champions League game of the season.
The Gunners reached the semi-final stage of the competition last season, losing to eventual winners Paris St-Germain.
Arsenal beat Athletic Bilbao 3-0 in their final pre-season game of the summer, but have some injury worries coming into this fixture.
Captain Martin Odegaard came off with a shoulder problem in the win over Nottingham Forest on Saturday and has not travelled to Spain.
The Gunners are also going to be without Bukayo Saka and Ben White, who has a minor issue and did not train.
However, Arsenal have been given a boost as William Saliba is back in the squad after missing the match on Saturday with an ankle problem.
Image source, Getty ImagesDavid Raya says Arsenal have "belief" they can win the Champions League after suffering a painful defeat by eventual winners Paris St-Germain in the semi-finals last season.
The Spain international goalkeeper - who turned 30 on Monday - has kept 42 clean sheets in his 100 Gunners appearances but has not lifted a major trophy with the club despite his impressive impact.
"We have belief, we want to win," he told media before Tuesday's Champions League opener against Athletic Bilbao.
"We are Arsenal and we play to win. It is not a doubt, that is what we play to do. That is what we play football for.
"It's a long journey, a long season, in the Premier League and Champions League so we are focused in the present.
"We want to go higher this season, that's what we want to do."
When pushed on what the Gunners learned from that PSG defeat, Raya added: "That it hurts a lot losing in the semi-final. You get more mature.
"It is incredible to be here."
Kepa Arrizabalaga became Arsenal's first full-time goalkeeper signing since Raya when he joined from Chelsea in the summer, and his compatriot is relishing the challenge.
"Competition is all over the place, you need competition to get out the best [in yourself]," Raya added.
"Kepa and me, we have a good relationship. It's a pleasure to share dressing room with him."
Arsenal boss Mikel Arteta has been speaking to the media before Tuesday's Champions League game against Athletic Bilbao (17:45 BST).
Here are the key lines from his news conference:
Gabriel Martinelli, Kai Havertz, Ben White and captain Martin Odegaard will all miss the Gunners' Champions League opener. He added that Odegaard has not travelled with the squad.
Providing an update on Bukayo Saka's fitness, Arteta said: "There's still quite a lot of things to go through. Very difficult to understand what week he is going to be available. He will most certainly be pushing to be available as soon as possible."
Asked if Arsenal are better placed to win the Champions League now: "That's the aim in the beginning but we all know it's going to be a really long journey. The margins in this competition are very small and you have to be at your very best from day one to give yourself the best chance."
What has the team learned from last season? "That we are good enough, that we can compete against any opposition on the day. You have to have two things go your way. You have to have a full squad available at critical moments and have to put the ball in the net when the chances come your way."
More on last season's run to the semi-final: "We were very unlucky in the semi-final not to get through. You take a lot of learning from that, it's not only what we feel but the expectations that we have created and the real conviction that we can go all the way. We showed a very good level of consistency throughout the competition and we need to lean on that and try to be better."
He is "excited" to begin a new European campaign in the area where he grew up: "A beautiful place and stadium we know is going to create something special."
Listen to live commentary of Athletic Bilbao v Arsenal on Tuesday from 17:45 on BBC Sounds
Image source, Getty ImagesAthletic Bilbao coach Ernesto Valverde thinks Arsenal are one of the favourites to win the Champions League this season, speaking ahead of his side's fixture against the Gunners on Tuesday.
"Arsenal are totally focused on this match," said Valverde. "They are one of the favourites to win the Champions League because of their skill, tactics, and the winning spirit their coach Mikel Arteta has given them.
"It's the start of the Champions League and we're playing against a high-level opponent, the kind that Bilbao likes, but we have to be very careful and take advantage of opportunities. Arsenal won't be forgiving."
Bilbao forward Inaki Williams added "We are playing against a great team, one that shows no mercy. We have to make the most of the chances we get."
Alex Howell
Football reporter
Image source, Getty ImagesWilliam Saliba looks to be in contention for Arsenal's opening Champions League game with Athletic Bilbao on Tuesday.
The France centre-back missed Saturday's 3-0 win over Nottingham Forest. He did train with the team before that match, but said to manager Mikel Arteta he felt he needed some more time.
In the pictures of Monday's training session that are available, it does not look like Bukayo Saka, who is missing with a hamstring injury, or Martin Odegaard, who came off with a shoulder problem on Saturday, were in the session with the main group.
We asked for your thoughts after Saturday's Premier League game between Arsenal and Nottingham Forest.
Here are some of your comments:
Arsenal fans
Mike: Very confident display and showed the great benefit of Arsenal's active transfer period. The new boys all acquitted themselves extremely well. Keep up this excellent start and we will have a real chance of total success.
Vince: What a complete victory and to think the new boys haven't had much time to bed in. If all goes well, the second half of the season should prove to be great watching for us Gooners!
Ryan: Last year, losing Saka, Havertz, Saliba and Odegaard (plus no Rice) would have probably led to a shaky win or, more likely, dropped points. The strength in the squad now means that four definite starters are not missed. Get through this tough first three months of the season close to the top and Arsenal will be in good shape.
Barry: With the players we now have, barring too many injuries, this could be our time to win the league.
Phoenix: A good way to forget the loss at Anfield - good ball play from the guys. Just happy for Viktor Gyokeres and Zubimendi is a colossus of a player - small in nature, big in performance. Trophy is the currency that the team needs going forward.
Forest fans
Andre: I was expecting a larger defeat, to be honest. We need to bring in the new signings. Never been a fan of our new coach. Seems he is doing the same job when he was at Tottenham - taking us down the league!
Stephen: Forest haven't won at the Emirates for a while. No Ange effect either. Needs to start winning big time with all the new recruitments.
Mossy: Losing players this early in the season does not bode well, with games coming up quick and fast. Morgan Gibbs-White and Callum Hudson-Odoi are shadows of the influential players of last season.
Steve: This is a disaster appointment by an owner who had a mardy and dumped our best manager for years!
Russell: Let's have some patience - Arsenal are a top side.
