Wilshere's previous Arsenal league appearance came on the final day of the season in May 2011 and he missed the whole of the last campaign with niggling ankle and knee problems, which ruled him out of Euro 2012 and the London Olympics.
"I made the decision without telling him because when you have not played for such long time it is not always easy to deal with that and there is a high level of expectation when he goes on the pitch," said Wenger.
"I told him he was playing at 10.30am today. Sometimes I think it is better when you don't have much time to think about it when you have been out for a long time. I also felt the confidence of the team was a bit jaded and sometimes player with experience and quality give a bit of a lift as well."
The 20-year-old's first touch was greeted by huge cheers, and he got through a testing 67 minutes, with Mikel Arteta's late scrambled effort making it a positive afternoon all round following a testing spell for Arsenal.
Wenger felt Wilshere came through the game with a lot of credit, going up against a combative QPR midfield of Samba Diakite and Esteban Granero.
"You could see technically he is there, and he gave everything, but what is missing he will get through competition," said Wenger. "Jack still misses a bit of the pace of the game, the rhythm of the game, but overall what he did was class."
It was far from a vintage Arsenal display against a hard-working QPR side and an inspired performance by goalkeeper Julio Cesar, who was finally beaten by Arteta's effort with eight minutes left after full-back Stephane Mbia had been sent off for kicking out at Thomas Vermaelen.
QPR manager Mark Hughes felt Arsenal's goal was offside. He said: "I have seen the replay, Arteta is offside twice, on the initial header that Julio saves and in the melee he comes back from an offside position and scored.
"How the referee hasn't given offside, I don't know. We have gone in and asked for an explanation and he has come up with some explanation about Ryan Nelsen leaving the field of play so that played everybody onside. I have no idea what he is going on about, but that's what you're up against."
Source: PA
Source: PA