Barcelona v Liverpool (20:00 BST)
Barcelona manager Ernesto Valverde on Liverpool: "They play with a great level of pressure and rhythm. They'll be a very difficult opponent to beat.
"Our intention is to win, but we know the value of stopping them from scoring."
I miss Xabi Alonso. What a footballer!
Image source, Getty Images#bbcfootball or text 81111 (UK only)
Nicky Carr: Don't want to jinx us but I just have a really good feeling about LFC at the moment. We look strong in defence and attack. I think we'll sneak it tonight and play them off the park next week! Soo excited for this game. Bring on Messi.
Barcelona v Liverpool (20:00 BST)
*An exclusion from the Bingo card!*
Everyone's talking about Philippe Coutinho. He left Liverpool for Barcelona for a whopping £142m last January.
That money essentially helped to pay for the signings of Virgil van Dijk, Fabinho and Naby Keita, among others, but his departure left a few sour grapes.
Complaints of a back injury and a transfer request on the opening day of the season - it wasn't the smoothest of departures.
He's struggled since the move but Spanish football expert Andy West has looked at whether he can still haunt Liverpool tonight.
Image source, Getty ImagesBarcelona v Liverpool (20:00 BST)
BBC Radio 5 Live
Pako Ayestaran, who was Liverpool’s assistant manager when they won 2-1 at Barcelona in 2007, spoke to BBC Radio 5 live earlier:
“They were the holders but in that moment they were on their way down, 2006-7 Barcelona was not the same – but always it’s tough, always it’s tough, to play at the Nou Camp…
"To have an opportunity to win there, you have to be perfect and you need a bit of luck as well."
Image source, Getty Images#bbcfootball or text 81111 (UK only)
BeeElleDoubleU: Emma, I believe the UCL is the best tournament because it means more to win it. As there are lots of superb teams all playing in it at such a high level. So to win it is a massive achievement! Which LFC have done 5 times, just sayin' Dearie.
*Bingo card alert!
What a night that was in 2007!
I remember it like it was yesterday. Craig Bellamy's golf swing celebration, John Arne Riise's goal (with his right foot!) and Rafael Benitez consoling Deco at full-time...
I've just given you two (three with the picture below) of the Liverpool players who featured that day but can you name the other 11?
(I'm going to post a picture of the whole team in a few minutes so don't cheat. Take the quiz then come back. Play fair!)
Image source, Getty ImagesBarcelona v Liverpool (20:00 BST)
The Nou Camp is one of the toughest places in world football to go. Barcelona are unbeaten in 31 Champions League home games.
But Liverpool seem to do pretty well there. They are the only English side to win away at Barcelona in European competition.
The last was a 2-1 victory in the 2006-07 Champions League and Liverpool have progressed from eight of their previous 10 semi-finals.
Image source, Getty Images#bbcfootball or text 81111 (UK only)
Ian Goldsworthy: I think Steve Cooper [5:50] is mixing up his bingo with cricket...Its not Boycott Bingo!
Sean Turner: I'm guessing it'll be a full house in the Nou Camp tho!
I don't know what I'm more pleased about - people not hating my bingo idea or people making bingo-based puns.
Barcelona v Liverpool (20:00 BST)
It's a bank holiday in Barcelona today meaning football fans are having to plan their journeys using public transport more wisely due to a reduced timetable.
I googled and apparently it's Labour Day, which is an annual holiday to celebrate the achievements of workers in Barcelona.
So, there you go. But hopefully travelling fans will get to the Nou Camp on time and there won't be any issues.
Barcelona v Liverpool (20:00 BST)
Messi has scored 24 goals in just 32 Champions League matches against English opposition.
But he has failed to score in his two previous appearances against Liverpool. So he's obviously not that good...
Image source, Getty Images#bbcfootball or text 81111 (UK only)
Steve Cooper: Let's hope it's not a bingo score by Barca, Emma! Keep Messi under control!
Some more messages of support for Iker Casillas from tonight's teams.
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
Barcelona v Liverpool (20:00 BST)
Will Roberto Firmino be fit to play tonight? That's the question everyone wants to know the answer to.
Jurgen Klopp said he'd wait until the day to assess him. Firmino missed the game against Huddersfield on Friday with a muscle tear.
This is what the boss said yesterday...
"If Bobby is 100% ready to play, then he will maybe play. He's here [in Barcelona]. He trained today. We have another session and maybe I have to make a decision."
Image source, Getty ImagesBarcelona v Liverpool (20:00 BST)
Barcelona come into this match on a high having sealed their 26th (26th!!!!) La Liga title with a 1-0 win over Levante on Saturday.
And they have unfinished business in the Champions League.
Despite trumping bitter rivals Real Madrid in Spain, they have fallen short in Europe and had to watch them win four of the last five Champions League titles.
After three successive quarter-final defeats, Barcelona are considered favourites to go all the way in Madrid this year.
Victory in this two-legged tie would seal their first final since 2015.
We have been asking BBC Sport readers to send in their thoughts on whether the Champions League is the best competition in football.
Is it better than the World Cup? Epic comebacks; record-breaking all-English classics; the world's biggest superstars...
Get involved and contact us here.
Image source, Getty ImagesBarcelona v Liverpool (20:00 BST)
Liverpool are aiming to reach back-to-back Champions League finals and become the first English club to do so since Manchester United in 2009.
They are pursuing their sixth European title and their first since that victory over AC Milan in 2005.
In contrast, four of Barcelona's five titles have come in the past 13 years.
Last year's run to the final came after Liverpool had failed to qualify for the competition in the previous season.
Basically, Jurgen Klopp is working wonders and Liverpool's progression has shot up in recent years but Barcelona are still the big boys.
Image source, Getty ImagesBarcelona v Liverpool (20:00 BST)
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
Barcelona v Liverpool (20:00 BST)
I've decided there's so much chat in the build-up to this match that we should play Champions League Bingo.
Basically, if I* or any TV pundits/commentators mention any of these five things during the match, you can cross it off the list and have to let me know.
*I will have to mention lots of these things in the build-up so it's only valid during the game!
If you missed the game last night - like my flat mate who was catching up on Line of Duty - then you can check out Phil McNulty's match report from the Tottenham Hotspur Stadium.
In a nutshell, Tottenham were awful in the first half, better in the second half but not good enough overall. Ajax were wonderful in patches and have one foot in the final in Madrid.
You'd still fancy Barcelona or Liverpool to beat them though wouldn't you? Surely?
Image source, Getty Images