Cesc was taken off at half time against Portmsmouth after tweaking his hamstring, but at the present time it's not clear how much damage has been done.
Arsene Wenger said after the game:
Arsene Wenger said after the game:
"If it is a little pull, he will be out for three weeks, if it is just tightness, maybe he can get away for Wednesday. In 48 hours, we will have a better view."
I believe if there's any doubt as to his fitness, Wenger will err on the side of caution and rest him for the two trips to Manchester - time will tell.