Fabregas doubtful for Old Trafford trip
The Spaniard missed Arsenal's Champions League playoff victory over Celtic on Wednesday after injuring himself in the defeat of Portsmouth last weekend.
"He had a training session today that was quite positive," Wenger, whose side have scored 10 goals in two league matches, told Arsenal's website on Thursday.
"He will have a definite test tomorrow where we will decide if we include him in the squad or not. Today I would say it is a real 50:50. Yesterday it I would say it was 60:40 against but he looked positive today."
Theo Walcott and Tomas Rosicky are also unlikely to play in the Old Trafford clash, the first meeting between any of the established big four sides this season.