The England international has seen his role for club and country scrutinised this season following some subdued displays, notably in the recent World Cup qualifier against Kiev in Ukraine.
Wilshere has been deployed on the left with new arrival Mesut Ozil impressing and Aaron Ramsey flourishing in the middle following a long injury lay-off.
But Wenger is confident that the 21-year-old, who missed Euro 2012 and the London Olympics with fitness issues of his own, will soon be back to his all-action best.
"There are similarities (to Ramsey) because it takes time to come back to your best physically," Wenger said.
"However, you could consider Jack was ahead of his age before he was injured, it is not the same. Aaron Ramsey had to make his way there.
"For Jack, I think it is more a fitness problem than anything else, but that will come back much quicker than the rest.
"Aaron had heavy metal in there (to pin his double leg break), and also the psychological impact of the injury, it took him a while to get back. When he was injured he was not there, he was still in a development phase.
"Fitness wise Jack is between 80-90% of his potential. For the rest, he has not a lot to learn - he understands the game, can play anywhere, defensive midfield, central midfield. He is a complete player, Jack."
Ozil has impressed on his two performances so far, helping to set up Olivier Giroud for the opening goal at Sunderland, and Wenger believes he could be the key to unlocking Stoke on Sunday.
"Before you could get the cross in and the guy could jump over everybody and head the ball in - today you have to find him through little pockets, maybe this is why this kind of player (Ozil) becomes more important because that creative aspect needed is higher," Wenger added.
"Ozil is a similar type to (Dennis) Bergkamp. He created a lot, but Dennis' evolution through his career was an adaptation to his physical qualities - when he could not score any more he became a great provider."
Watch Arsenal v Stoke live on Sky Sports 1HD from 12.30pm on Sunday.