Wilshere, 20, has not kicked a ball in anger for the Gunners in more than a year, spending the whole of last season sidelined by a niggling ankle problem which also ruled him out of contention for Euro 2012 and the Olympics.
Wenger feels Wilshere is making good progress towards a return by the end of the new year, which the manager revealed was one of the reasons why he cooled on a move for Turkey international Nuri Sahin from Real Madrid.
"October will be an important month for Jack," said the Arsenal manager.
"I will promise you that I will be careful, but Jack works very hard.
"Every day he is in early, late going home, is focused and has built up a good basis for his body.
"After how quick he will be sharp again for competition, I don't know. We will have to wait for at least a month to see that."
Wenger feels the proposed loan move for Sahin, who is also on Liverpool's radar, could yet be resurrected should he decide another attacking midfielder is what he needs.
However, having sold Alex Song to Barcelona, a more defensive option is also a possibility ahead of the transfer deadline.
"I didn't say it was dead, I said it was not alive. It can resuscitate. It can become alive again," the Arsenal manager added.
"He wouldn't necessarily be a replacement for Song because Sahin isn't a defensive midfielder.
"I see Sahin as not a deep, deep midfielder, but a little bit higher.
"We have Wilshere coming back quicker and he is a similar type of player.
"But of course Sahin wants to join a club where he will play. We have nine midfielders and they all need a chance to play."
Arsenal lacked a cutting edge in attack against Sunderland on the opening day, playing out a frustrating goalless draw in their first match since captain Robin van Persie was sold to Manchester United for £24million.
Wenger accepts his frontline - which could again include summer signings German striker Lukas Podolski and France forward Olivier Giroud - must do better at Stoke on Sunday.
"Overall we are equipped but up front we have to show we can compensate for the departure of Van Persie," the Arsenal boss added.