Wilshere has had a torrid time with injuries in his short career so far, including missing the entire 2011-12 season and European Championships that summer with a persistent ankle injury.
The 21-year-old England international has managed to feature more regularly for club and country so far this season, and Wenger believes that more consistency could be the key to him fulfilling his potential.
"Jack has the personality to be a top, top, top player. He has gone through a difficult period," the Arsenal boss said, according to PA.
"The problem in the modern game, you need to be absolutely 100% physically (fit) to express your talent, or you don't.
"At the moment Jack is not completely at his best physically, that is why people start to question his performances, but I think he is a fantastic footballer and he will show that. He needs consistency now."
Wilshere has featured in all five of Arsenal's competitive matches so far this season.