Craig Andrew Smith: Come on #Arsenal, external, pretend it is still October.

Raheem Sterling is finding plenty of space down the right and he now drills in a dangerous cross which Marc-Andre ter Stegen has to come and field on the bounce. City having a strong spell. 

Bayern Munich need to win tonight (and hope Atletico don't lose to Rostov) to clinch their spot in the last 16.

Well, it's not going so great for the German champions, who trail 1-0 to PSV. Santiago Arias heads the Dutch side, who need a result to stay in the tournament, 1-0 up. He was miles offside - Manuel Neuer is furious - but the goal stands.

Robert Lewandowski earlier hit the crossbar with a header.

Hishaam Habib: City were robbed. That should have been a penalty.

Jason Moore: Absolutely a penalty. Sterling was stupid in exaggerating so much but there's enough contact for it to be a foul

Phil McNulty
BBC Sport chief football writer at The Etihad

Manchester City's fans fired up and furious after Hungarian referee Viktoe Kassai books Raheem Sterling for diving when it looked like a penalty after he was brought down by Samuel Umtiti.

City made a slow start but seem to have come to life fired by that sense of injustice.

So two goals within three minutes for Ludogorets Razgrad and lots of you seem to be unhappy with the defending..

Phil: Absolutely shocking defending, shouldn't have conceded that. Hope we get back from this.

Marauding Mauro: I have 38 questions about what Ospina was doing on that goal.

Cody Sparks: That was atrocious set-piece defending.

Have your say at #bbcfootball on Twitter or text 81111.

Simon Stone
BBC Sport at the Etihad Stadium

There will be plenty of City fans quite pleased there has been no early goal at the Etihad Stadium tonight.

Virtually every turnstile had long queues outside as the Champions League anthems were being played to mark the City and Barcelona teams arrival on the pitch.

Many didn't make it in for kick-off, for a game you don't really want to be late for.

Peter Collins: Last time City were better for an hour but didn't score. If they are clinical they can beat Barca. Big if though.

Ally McCoist
Former Scotland striker on BBC Radio 5 live

Unless I'm completely wrong, that's a penalty! He definitely catches him.

Image source, Rex Features

Is that a penalty?! Raheem Sterling cuts inside Samuel Umtiti and goes to ground, and he's booked for a dive!

Referee Viktor Kassai has made a big call there. Sterling went down easily, but Umtiti left his foot in there. It came at the end of a cracking counter, with Sergio Aguero charging down the right. 

Image source, Reuters

Fernandinho a mite lucky to avoid a booking for a heavy challenge on Ivan Rakitic and Lionel Messi rather wastes the free-kick. 

Well Arsenal have started like a team keen to put this game to bed early on. Francis Coquelin plays in Mesut Ozil galloping into the penalty area but the German doesn't really get hold of his shot and it's a comfortable save for Milan Borjan.

John Wright: Hard to beat MSN but Bobby Robson's Barca 1996-97 front 3 not too shabby: Stoichkov, Ronaldo, Figo

Oh yes, now we are talking. Ronaldo may just trump anyone for me...

Image source, Getty Images

Stoke v Swansea was 1-1 by this stage last night. Just saying. 

Aaron Ramsey has the first effort of the night, launching himself into an overhead kick but it flies well wide. He should have left it - Olivier Giroud was free behind him. Arsenal have started well though. 

Image source, Reuters

Yusuf Olatunji: City can't withstand Barcelona attacking hurricane.

Kieran Desouza: I think a City win tonight. They had a defensive disaster at the Nou Camp by conceding 4 goals and a penalty. The Ethihad stadium is always tough to go to and get a decent result and judging by Barcas league results, City have to be favourites tonight.

What do you think? Get involved at #bbcfootball on Twitter or text 81111.

Aaron Ramsey is playing wide right for Arsenal on his return tonight, his hair almost matching the fluorescent trim around the Gunners' away kit. This must be strongest Arsenal squad in many a year. Lots of options and depth for Arsene Wenger. 

Image source, EPA

Luke: Ref 19:31 - Hard to call, Messi miles ahead of them all. Henry better than Suarez and Neymar. Ronaldinho a genius and Eto'o a goal machine.

John McEnerney: Can't put into words what Ronaldinho did for FCB in his first 2 years he wasn't surrounded by the class MSN are! Pure, pure magic!