Diaby, 25, has been plagued with injury in recent seasons, and this campaign the France international has failed to make a Premier League start due to further fitness troubles.
Wenger, though, believes Diaby has the potential to be a "massive" player for the club, and the midfielder has thanked the Gunners for their ongoing support with his injury frustrations.
"I just need to carry on and stay focused every day in my rehabilitation," he told Arsenal Player. "I feel in a good way now.
"Football itself has motivated me because it's the thing that I love. There is also my family and team-mates, manager, medical staff - they have all helped me.
"It is a big motivation for me that the boss said about me [being a "massive" player]. I want to be thankful to him and show him that he is right."