Arsenal captain Cesc Fabregas will miss Tuesday's Champions League tie against Porto because of a hamstring injury he picked up against Burnley on Saturday.

The midfielder scored the opener in the 3-1 victory against the Clarets but was forced off in the 39th minute.
Gunners boss Arsene Wenger said: "We could not even take a gamble with him, so he is not available. We don't know how long he will be out for."

Arsenal must overcome a 2-1 first-leg deficit in the last-16 tie to progress.

Fabregas, 22, was sidelined for three weeks after aggravating the same hamstring in December against Aston Villa - a game in which he produced a 27-minute cameo appearance as a substitute and scored twice before limping off.

But Wenger said he was hopeful the Spanish midfielder would make a speedier return this time.

"Cesc is having a scan today and we are convinced it will only be a small time. He has a small chance of getting back for next weekend against Hull, but to play him again tomorrow would mean significant damage," Wenger added.

"Ideally we wanted him to be there but we want to qualify and the absence of Cesc is no excuse at all. We have enough players and a strong enough squad to get round that and have enough chances to qualify."
The Arsenal boss also refused to blame recent international duties for the injury setback, adding: "I cannot fault Spain, they only played him in one half against France. Cesc has given a lot recently. It is a re-occurrence in the same hamstring so we have to find out why it creates some problems."

If the Spanish international is sidelined for a lengthy period it could seriously damage Arsenal's hopes of winning the Premier League title, with the Gunners two points behind leaders Manchester United and level on points with Chelsea, who have a game in hand on their rivals.

Abou Diaby replaced Fabregas on Saturday and could stand in again on Tuesday.

More positive news for Arsenal is that veteran defender Sol Campbell did train on Monday and looks likely to be fit to face the Portuguese side following a groin problem. The former England international is in line to play because William Gallas has been ruled out because of a calf injury.

The Gunners have also named goalkeeper Manuel Almunia as captain for the night, who returns to European action following a nervous performance from Lukasz Fabianski during the side's first-leg performance.

The Polish goalkeeper was at fault for Porto's opening goal and also picked up Campbell's pass for the free-kick that led to the home side's second-half winner.

Almunia said: "This squad is very young, and if anybody needs help, I am here for them.

"My role will be the same as when I am not captain and just in goal. I have the personality and will help the team as I do normally every game. The armband does not change anything in myself."

Porto have lost their last six matches in London and suffered their heaviest Champions League defeat early last season at the hands of Arsenal at the Emirates, going down 4-0.