Lou: Liverpool defence is a worry for me.

Atmos: 4-0 PSG.

Criss: City all the way.

Sylvain Distin
Former Manchester City defender Sylvain Distin on BBC Radio 5 Live

People expect some magic from Lionel Messi, but for me Man City are a much more complete team, not just a team of individuals and that's going to be a problem for PSG.

City are really good at pressing, recovering the ball once they lose it and I feel that it will be too much for PSG again.

City won't be planning to defend a lot they'll just want to keep the ball and the more Messi, Kylian Mbappe and Neymar are having to run around without the ball the more frustrated they will get, that's not their strength. But with their quality one of those three players could cause problems.

Manchester City

Manchester City boss Pep Guardiola to BT Sport: "What a pleasure to be here.

"I thought about making more changes but this kind of game, the players won't be tired because they're so excited. The trip was comfortable, the hotel is magnificent, the city is so nice. No complaints. We have got five days until the game in Anfield.

"They [PSG's stars] are too good to control all the game. We have an idea with a game we want to do and we'll try."

Tonight's venues looking very photogenic.

Manchester City are playing in Paris' Parc des Princes, while Liverpool are at the Estadio do Dragao in Porto.

Image source, Getty Images

Image source, Getty Images

The full-time whistle has blown in both Amsterdam and Kyiv.

Sebastien Haller’s fifth goal in his first two Champions League games (a feat no other player has achieved) helps Ajax to a comfortable victory against Besiktas.

Meanwhile, Italian champions Inter Milan are still searching for their first win in Europe this season after being held by a determined Shakhtar Donetsk.

Captain Andriy Pyatov made two fine saves late on to ensure the spoils were shared, with the 37-year-old Shakhtar goalkeeper denying Joaquin Correa and Stefan De Vrij.

Liverpool

Image source, Getty Images

Liverpool are no strangers to Porto.

They have faced each other five times since Jurgen Klopp took charge, with the Reds winning three of them.

In fact, Liverpool have a very good record against Porto in those encounters - scoring more goals (11), keeping more clean sheets (three) and recording more wins (three) than against any other opponent in the Champions League under Klopp.

Liverpool

Liverpool boss Jurgen Klopp speaking on BT Sport: "It’s difficult obviously (learning of Roger Hunt's death).

"We don’t know these legends personally but the first thing you learn when you come to Liverpool is about these guys. He would have been a player that would have played definitely in my team. It is really sad. Condolences go to his family from the Liverpool family. It is a really sad day."

On Trent Alexander-Arnold and team selection: “Unfortunately shortly after training he went in early and we did a further assessment.

"He is out for today for sure and it does not look great for the Manchester City game as well. He thought it was tight but it is a little bit more than that.

"It’s always a question of fresh legs or rhythm we decided this time for rhythm. Normally you have to rotate but in this situation we don’t have to the boys can go again."

On Jordan Henderson's 400th appearance: "It’s a big number and a lot more to come. If he stays fit he will easily make 500."

Liverpool

Image source, BBC Sport

Liverpool

Liverpool boss Jurgen Klopp said their defensive display against Brentford is "not a concern" ahead of tonight's game.

The Reds' 3-3 draw on Saturday was the first time they conceded three in a match since the European defeat by Real Madrid in April.

"We didn't defend at our highest level so we have to improve," said Klopp.

"We don't make these things bigger than they are but you have to show a reaction.

"It's not a moment to be concerned but we have spoken about it and we know that we can't do things like that. We have sorted that and we have to show that."

Simon Stone
BBC Sport

Image source, Getty Images

It is only a matter of months since Manchester City beat Paris St-Germain home and away to reach their maiden Champions League final, where they were beaten by Chelsea.

Riyad Mahrez was not reading anything into that victory though, especially considering PSG have a few new players, including Lionel Messi and Sergio Ramos.

"It is a different match," he said.

"Last season was a semi-final with no fans. Today is six months later, beginning of the season and the group stage.

"It will be another tight game and we will have to be focused like we were last season. We don’t think that because we won last season we will win again."

Julien Laurens
French football expert on BBC Radio 5 live

If you sign one of the greatest, if not the greatest ever, you become that team that should win the Champions League because he's won it before. If you already have a team that was out in the semi-final last year and the final the year before, then you add Lionel Messi of course you become the favourite.

Even if there are a lot of things to work on still with Messi in the team, Messi in any team makes it exceptional. The expectation is that he should bring this team even closer to the title that they are craving but as we all know it's not as simple as that. It's a lot more complicated than just bring Messi to Paris, add him to this very good team and he'll win it for you. But that kind of talent can only be a good thing for any team in the world.

Shamshad Mohammed: PSG have to make a statement today! Waiting for an amazing match!

Image source, Getty Images

Image source, Getty Images

Paris St-Germain boss Mauricio Pochettino has played down any falling-out between Kylian Mbappe and Neymar.

Mbappe appeared to complain to a team-mate on the bench "he doesn't give me the pass", seemingly about Neymar, after being replaced late on in Saturday's win over Montpellier.

"They are fantastic guys. These things happen," said Pochettino.

"There are always things between top players. They are competitors who want to win and help the team achieve good.

"I have spoken to them individually. They may have also spoken to each other and there have been photos of them enjoying ourselves in training.

"If there is a small incident sometimes that can create a wave but it is actually just talk."

Michael Brown
Former Leeds midfielder on BBC Radio 5 Live

Man City have got a good chance of winning - it was a wonderful performance at the weekend against Chelsea. Phil Foden and Gabriel Jesus are a bit unlucky to be replaced but I think it's sensible from Pep Guardiola with the games coming in quick succession.

Bernardo Silva was excellent at the weekend, Kevin de Bruyne and Jack Grealish, these are the games that they have got to show quality, got to deliver and go past people with confidence and swagger. They need to be a brave and take the ball on early on in the game.

Grealish must be absolutely delighted to be walking out here tonight, this is why he signed for City. But he has to have that confidence to take the ball and keep trying if it doesn't work and make something happen. Can he be exciting tonight?

Manchester City

Image source, Getty Images

In the opening group game against RB Leipzig, Manchester City’s Jack Grealish became the first Englishman to both score and provide an assist on his Champions League debut since Wayne Rooney in September 2004 (v Fenerbahce).

Grealish is looking to become the first English player to score in both of his first two appearances in the Champions League.

Image source, BBC Sport

Porto boss Sergio Conceicao makes five changes from the side that won at Gil Vicente in the Portuguese top flight last Friday.

Pepe returns in defence with Chancel Mbemba suspended, while the likes of Sergio Oliveira and Toni Martinez also start.

Porto XI: Costa, Corona, Pepe, Diaz, Marcano, Martinez, Otavio, Sanusi, Oliveira, Taremi, Uribe

Subs: Cardoso, Conceicao, Costa, Evanilson, Grujic, Mario, Manafa, Marchesin, Pepe, Vieira, Vitinha, Wendell

Liverpool boss Jurgen Klopp makes one change after the draw at Brentford in the Premier League.

James Milner replaces Trent Alexander-Arnold, who misses out with a sore groin. Jordan Henderson makes his 400th Liverpool appearance.

Liverpool XI: Alisson, Milner, Matip, Van Dijk, Robertson, Jones, Fabinho, Henderson, Salah, Jota, Mane.

Subs: Adrian, Kelleher, Konate, Keita, Firmino, Gomez, Oxlade-Chamberlain, Minamino, Tsimikas, Origi, Phillips, Williams.

Nedum Onuoha
Former Manchester City defender on BBC Radio 5 Live

These managers and clubs speak for themselves and the expectation is to be winning things. PSG made the Champions League final the year before last and the semi-final last year and went out to Man City and they had an injury to Kylian Mbappe for the second leg and were probably disappointed.

But you don't bring Lionel Messi in just to win the Ligue 1 title you're bringing him in to try and be the best team in Europe and win the European title.

Image source, Getty Images

Manchester City face the prospect of lining up against a front three of the two most expensive players ever, in Neymar and- Kylian Mbappe, and record six-time Ballon d'Or winner Lionel Messi.

"With this amount of quality I don't know how to stop them," said Pep Guardiola.

"They're so good. This amount of talent makes it so difficult.

"You have to defend well without the ball and let them run when we have the ball. They are exceptional players, individually and they combine so good.

"The three players up front can do whatever they want. Wide narrow, wide left, Messi can play right or middle, Mbappe wide or middle. They combine so well, the talent cannot be stopped."

Michael Brown
Former Man City midfielder on BBC Radio 5 Live

Image source, Getty Images

The supporters are starting to leak in and the pitch looks magnificent - seeing the teams and the set ups we're in for a real treat. And Lionel Messi is playing!

Ruben Dias, Aymeric Laporte, Joao Cancelo and Kyle Walker playing against Messi, Neymar and Kylian Mbappe, it doesn't get any better than that as a combined group - how do they come up against them? How physical can they be? Do they go tight or drop off?

It's fascinating to watch teams when they come up against these world-class players. We know that PSG don't always play together, they're quite individual and they're going to have to be a bit more combined to beat this City side.