Arsenal face missing skipper Cesc Fabregas for next Saturday's clash with Manchester United with a hamstring problem.
There are fears that the Gunners skipper could be out for three weeks after being subbed at half-time in the 4-1 thrashing of Portsmouth, says The Sun.
Gunners boss Arsene Wenger said: "Cesc has a hamstring problem. He will be short for Wednesday certainly.
"If it's a little pull he'll be out for three weeks. If it's just a tightness maybe he can get away for the Celtic game but after 48 hours we'll have a better view."
It will be a massive blow for the Gunners as the Spanish midfielder has been in top form this season.