Fabregas out of Celtic second leg
The 22-year-old Spain midfielder, who excelled in the 2-0 first-leg win at Celtic Park on August 18, suffered a hamstring injury in the Premier League game with Portsmouth on Saturday.
"His scan was quite reassuring as he has no muscular strain but it will take a few days to settle down," Wenger was quoted as saying on the official Arsenal website .
Fabregas could also miss the Premier League clash with champions Manchester United at Old Trafford on Saturday, though Wenger remained optimistic he could play a part.
"There's a chance he'll be fit for Old Trafford," the Frenchman added ahead of Arsenal's return leg with Celtic.
The winners of the Champions League playoff tie will go through to the lucrative group stage.