Champions League Team News:Arsenal captain Cesc Fabregas has been ruled out of tomorrow's Champions League clash with Porto because of a hamstring problem while AC Milan striker Alexandre Pato has been included in Leonardo's 22-man squad for their game against Manchester United on Wednesday.
Fabregas llimped off after scoring the opening goal in the 3-1 Premier League victory over Burnley on Saturday.
The tightness was in the same hamstring the midfielder injured earlier in the season, which kept him out of action at the turn of the year.
Gunners boss Arsene Wenger said: "We cannot even take a gamble, so he is not available."
Veteran defender Sol Campbell did, however, join in training and he looks set to recover from a groin problem in time to face the Portuguese side, who will take a 2-1 lead to the Emirates Stadium for the second leg of the last-16 tie.
Wes Brown's suspected broken metatarsal has added to Manchester United's injury woes ahead of AC Milan's visit on Wednesday.
Brown picked up the injury against Wolves on Saturday and there are concerns that the England defender may have broken his fifth metatarsal, the one that takes the longest to heal.
Although Brown should have recovered in time for the World Cup, the timing is bad for Alex Ferguson who is also without John O'Shea (leg), while centre back Jonny Evans missed the Wolves game.
Ferguson also has concerns over Wayne Rooney (knee) and is without Michael Owen out for the season, while Anderson (knee) and Ryan Giggs (arm) are out.
Ferguson has already confirmed Dimitar Berbatov is likely to start against Milan, saying: "Rooney is very doubtful for the Milan game unfortunately. It's one of these bad bits of luck you get - the Wembley pitch has just killed him.
"I was pleased with how Berbatov did against Wolves though and I'll probably start with him on Wednesday."
Pato has been named Milan’s squad. The Brazil international missed Saturday's goalless draw at Roma having sustained a hamstring strain the previous weekend.
Pato will travel to England but whether the South American striker will be fit to play remains to be seen.
Milan must overturn a 3-2 deficit if they are to progress to the quarter-finals of Europe's elite club competition.
Pato has been in superb form for Milan this season, scoring 12 goals in Serie A and two in the Champions League.