The England midfielder finally returned to full training on Wednesday after an ankle injury sidelined him for the whole of last season, also ruling him out of contention for Euro 2012. Wenger, though, will take no chances with the 20-year-old, who is likely to have a few reserve outings before being considered for the first XI.
Speaking ahead of Sunday's trip to Manchester City, Wenger said: "We will see how he responds to the training now. We will have to be a bit patient, a bit cautious, because when a guy has been out for 14 months it takes a while to get back to match fitness."
Wenger added: "Jack is fit to practice and play, but to put high-level performances in takes time. He will need a few games in the reserves."
Combative midfielder Emmanuel Frimpong is also closing in on a return, having been sidelined by a serious knee injury suffered while on loan at Wolves in February.
However, goalkeeper Wojciech Szczesny will again be sidelined by the ankle problem which forced him out of the midweek Champions League win in Montpellier.
Wenger feels the Gunners can head to the Etihad Stadium in confident mood of a positive result, and does not expect the Blues' late defeat at Real Madrid to play a major impact.
"I expect them to be focussed and play well, but it was a disappointment for them of course. It always takes a little bit away from you," he said.
"But on our side, let's not have any speculation of the weakness or strength of them, let's focus on us to be at our best.
"If we are at our best I think we have a great chance to get a good result there."
Source: PA
Source: PA