He believes the injury is linked to a car accident in September, and he subsequently had surgery in November following Arsenal's 3-0 win over rivals Tottenham.
Wenger is also concerned that Cesc Fabregas and Robin van Persie may not be ready in time for the new campaign after their involvement in the World Cup final.
"Fabregas and Van Persie are due to come back on 5 August and from then on we will see how much build-up work is needed physically and as well how they have recovered mentally from the World Cup," added the Gunners boss.
"They might be short for the first game [of the season] but I don't know, that will depend on the fitness work they have done during the holiday."
However, Wenger said that he expects Denilson and Abou Diaby to be fit for Arsenal's final pre-season match, against Legia Warsaw on 7 August.
Although Johan Djourou suffered a hamstring injury in the 4-0 win over SC Neusiedl 1919 on Tuesday and Tomas Rosicky missed the match with a groin problem but Wenger has eased concerns over both players.
Bookmark with:
What are these?