Excellent defender from William Saliba. Galeno, all pace and skill, tries to go around the outside of the Arsenal man down the left wing, but Saliba isn't fooled by any of the tricks and defends it in style.

Neil Lennon
Former Celtic manager on BBC Radio 5 Live

How is that a yellow card for Kai Havertz?

It was a totally innocuous challenge, Varela came in on his blindside and he caught him with the elbow. It was a total accident.

Nothing Havertz could do there at all, all he was trying to do was protect the ball.

No shots on target for Arsenal, but now three in the referee's book with Kai Havertz joining Declan Rice and Jakub Kiwior. Havertz can feel a bit hard done by too.

Robert Lewandowski has been directly involved in 18 goals in his last 12 appearances in the Champions League knockout stages (12 goals, six assists).

Gunners left-back Jakub Kiwior with a booking after being humiliated by Francisco Conceicao.

He nutmegs Kiwior, who brings down his opponent.

Neil Lennon
Former Celtic manager on BBC Radio 5 Live

Image source, PA Media

The game is so scrappy at the minute, which will suit Porto perfectly.

Arsenal are being mature about it, approaching it with calm and taking their time. They just have to be patient and wait for the openings, even if only one or two arrive.

A change in the corner routine, this time it's Declan Rice who takes it and it is one from the training ground. Leandro Trossard is free, 10 yards out and catches it full on the volley, but doesn't have the technique to keep it down.

Gunners captain Martin Odegaard looks to test Diogo Costa, but his strike doesn't make it that far as Leandro Trossard is in the way with the ball bouncing off him.

Image source, PA Media

Francisco Conceicao with the most obvious yellow card you could ever see, for nearly ripping the shirt off the back of Gabriel Martinelli, who had been too good and too quick for the home man.

Ilkay Gundogan, a winner of this tournament last year with Manchester City, has a look at the Napoli goal but, under pressure, can only shoot well over the top for the visitors.

Image source, Reuters

Back under way too in Portugal. The two second legs from today's matches will both take place on Tuesday, 12 March.

Back to business earlier in Italy and Napoli have already improved. A cross is played to Matteo Politano and, with team-mate Victor Osimhen also in close attendance, he heads it wide after Napoli didn't threaten the goal at all in the first half.

Theo Walcott
Former Arsenal forward on BBC Radio 5 Live

Image source, Getty Images

This is a very tactical battle between the teams, not a good spectacle necessarily, but the game has gone how we expected it to.

Set pieces could make the difference for Arsenal in a game like this. Free kicks are free plays for a reason, so why not take your time with them and work on them and make them an advantage for you?

Arsenal have made it their mission to make the most of every set piece they get and this season it is really paying off.

This is the first time Napoli have failed to attempt a shot in the first half of a Champions League game, with tonight being their 59th match in the competition.

Image source, Getty Images

CM: Can we please stop focusing on Arsenal's set pieces? Is the game really that bad? Arsenal do score other goals you know.

Bayern Munich would like Xabi Alonso to replace Thomas Tuchel as their manager this summer, says journalist Raphael Honigstein.

Earlier today, Tuchel said he would be leaving Bayern at the end of the season.

Alonso, who could well guide Bayer Leverkusen to the Bundesliga title ahead of Bayern this season, has been heavily linked with the Liverpool role that Jurgen Klopp will vacate at the end of the campaign.

Spanish football writer Guillem Balague tells BBC Sport why Paris St-Germain striker Kylian Mbappe has agreed to join Real Madrid this summer.