Any idea?

John Bennett
BBC World Service in Valencia

"Gary Neville will have been told about these Valencia fans, he's getting an insight straight away. They are not happy with their team or the referee. Lyon have been the better side, the Valencia keeper making three decent saves.

"It's now a subdued atmosphere. As it stands Gary Neville and Valencia are heading for the Europa League, not the last 16."

Olympiakos had seven shots on goal in the first half but only one was on target. In contrast, two of Arsenal's four shots were on target. 

The Gunners are much more threatening where it matters.

Ian Dennis
BBC Radio 5 live senior football reporter at Stamford Bridge

Image source, Getty Images

"It's been a hard fought 45 minutes. Eden Hazard's through ball on 12 minutes, Diego Costa one on one, it was saved but the rebound cannoned in as an own goal. Chelsea have had a couple of other efforts - on the stroke of half time, Iker Casillas just got a touch with his finger tips to deny Costa.

"Porto have had three players booked so they must keep their discipline. Rememeber they need to score two goals a things stand to progress with Dynamo Kiev leading in the other game."

Mark Lawrenson
Former Liverpool defender on BBC Radio 5 live

"If Ramsey was OK he'd walk off. I hope he has not got caught on the old metatarsal. 

"It took Arsenal a while to grow into the game with such a noisy crowd. Olympiakos started lively but haven;t really looked like scoring. Once they scored the goal, they do look a much better side. At the moment, you'd think Arsenal would score the next goal."

Image source, Rex Features

So far so good for Arsenal, but possibly some concern over Aaron Ramsey. As the players head towards the tunnel, he is sat on the pitch, before eventually getting up and hobbling off. Injured?

Diego Costa is firmly in the thick of things as the first half heads towards a close. He's on the receiving end of a couple of tough challenges, resulting in yellow cards for two Porto players. He then shoots just wide of the far post on the stroke of half time.

As this graphic shows, Arsenal's goal came at the end of a sustained spell of possession. This screenshot is taken between 26 and 30 minutes.

Image source, Opta

Arsenal need a second if they are to go through, but they also cannot really afford to concede. They have a lucky escape when Laurent Koscielny swings a boot wildly at Brown Ideye's cross and the ball flies over his own bar. Moments later, Athur Masuako brings a good save out of Petr Cech.

John Bennett
BBC World Service in Valencia

Image source, AP

"Gnaly Cornet with a lovely finish from the right hand side. A curling effort with his left foot. Gary Neville frustrated. At the moment he and Valencia are heading into the Europa League."

Porto are enjoying plenty of possession (60% to be precise), but are struggling to hurt Chelsea. 

The visitors have not directed a shot on target as Chelsea, shown by our average positions graphic below, are content to stay compact and hit their visitors through pacy counters.

Porto are going out as it stands, remember, with Dynamo Kiev leading 1-0 against Maccabi Tel Aviv.

Image source, Opta

Mark Lawrenson
Former Liverpool defender on BBC Radio 5 live

"Walcott all over. Absolutely skipped past two tackles great balance, too easy, went to hit it and couldn't hit the target. He needs too many chances to score."

Disappointing from Theo Walcott as an attack that started out with promises fizzles out disappointingly. He breaks forward, gets to the edge of the area but fluffs his shot wide.

Image source, Empics

Spanish football journalist Mike Holden at the Mestalla: "Gary Neville hasn't moved from the edge of his technical area yet. He seems to be in continual dialogue with João Cancelo, most probably because he's the only player within earshot. He just also happens to be playing at right-back. No pressure, João."

It is still 0-0 in Valencia. Remember though, with Gent leading Zenit, even a win will not be enough for Gary Neville's new side.

Javier Hernandez has seven Champions League goals this season. Manchester United only scored seven on their way to a group-stage exit.

His Bayer Leverkusen side are still level at 1-1 with Barcelona. They need at least a win to stand a chance of progressing.

Mesut Ozil is bossing this game now. Wherever the ball is, the Germany international tends to be. #pullingthestrings

Image source, Opta