That's the first and so far only goal of the evening across Europe after 15 minutes.

Atletico Madrid 0-0 Lokomotiv Moscow

Borussia Dortmund 0-0 Red Bull Salzburg

CSKA Moscow 0-0 Lyon

That's the first goal AC Milan, unbeaten in 13 games, have conceded in seven games - a run stretching over a month.

Well now. Has Hakan Calhanoglu's honesty cost Milan a penalty? Almost certainly yes.

Arsenal's defence switch off again and Calhanoglu has a free run towards the box. Gunners keeper David Ospina comes flying off his line - the Milan player tries to hurdle over him but loses his balance and the chance is gone.

Obviously I'm not advocating anything, but a lot of players would have found the contact there and taken a penalty.

Image source, Reuters

Dreadful play by Arsenal. Callum Chambers gifts the ball to Hakan Calhanoglu and then Shkodran Mustafi comes charging out to close him down - leaving space for Patrick Cutrone to receive the ball and shoot wide. Let-off for the Gunners.

Image source, Reuters

Arsenal are coming into the game more and Sead Kolasinac's cross is only half-cleared. It's end to end now. The game that all neutrals were hoping for.

First chance for Arsenal as Henrikh Mkhitaryan's shot from Jack Wilshere's lay-off flies into the side netting. Mesut Ozil was involved in the build-up with a cheeky nutmeg.

Arsenal defender Calum Chambers is down injured as he appeared to bang his head into Hakan Calhanoglu's body. Looks like he should be fine to play on after treatment.

Arsenal do break into the box now but Danny Welbeck concentrates so much on holding off his marker that he doesn't actually control a cross into the box - and Milan get it away.

Andy Capontes: If Milan are half as committed as Gennaro Gatuso was as player then Arsenal will be in trouble! They need an away goal.

Alistair Bruce-Ball
BBC Radio 5 live at San Siro

Arsenal are under a lot of early pressure in a raucous atmosphere.

Milan almost lead as a cross is flicked on and Giacomo Bonaventura is inches away from turning it home at the back post. It's a corner - which Arsenal clear again.

But this is incessant attacks from Milan. Arsenal haven't really been past the halfway line.

Early corner to Milan as Patrick Cutrone's cross is deflected off Shkodran Mustafi. The Gunners get it clear.

Arsene Wenger will be praying his side don't concede early.

Cutrone wins another corner now.

Image source, Reuters

Shanmugaraja CK: It's ridiculous to be so negative even before the match starts. Can we all just shut up, keep our criticisms out for 90 minutes and just get right behind the team?

Under way in Milan.

Image source, Getty Images

Before all of tonight's Europa League games there will be a minute's silence in memory of Italy and Fiorentina defender Davide Astori, who died aged 31 at the weekend.

It is particularly poignant at the San Siro as Astori, whose funeral was held in Florence today, started his senior career with Milan.

Several Milan players, including captain Leonardo Bonucci, played alongside Astori for the Italian national side, while most of them played regularly against him in Serie A.

Image source, Getty Images

Joe Wedgwood: Wanted to see Ainsley Maitland-Niles today in middle or left back. Sead Kolasinac built like a tank but not quite performing lately. But get behind Arsenal tonight boys! We need support!

Vivek lamsal: AC Milan vs Arsenal, here we go again. Pathetic fans calling Wenger out. Let the game begin, get behind players.

Richard Elgar: We're playing AC Milan at the San Siro. Matches like this should be why you're a football fan. Get a life and get behind your team!

Here the players come. A large crowd at the San Siro welcomes them all out onto the pitch.

Image source, Reuters

Ryan Lloyd: Given that their only way of qualifying for the Champion's League next year is the Europa League, wasn't it a monumental oversight for Arsene Wenger to sell a good striker who was eligible for the Europa League (Olivier Giroud) and buy one who wasn't eligible (Pierre-Emerick Aubameyang)?

Christopher M. Selby: Arsenal 6-1 tonight.

Terryfic Otobong: I will be watching this game with my heart. I'll be praying under my breath. Arsenal really needs to win.

We'll also be bringing you updates from the other three games which kick off at 18:00 GMT.

Atletico Madrid v Lokomotiv Moscow

Borussia Dortmund v Red Bull Salzburg

CSKA Moscow v Lyon

And we'll keep this live page going after the Arsenal game for the four 20:05 GMT matches (as well as Gunners reaction).

Lazio v Dynamo Kiev

Marseille v Athletic Bilbao

RB Leipzig v Zenit St Petersburg

Sporting Lisbon v Viktoria Plzen