Wilshere was photographed with a cigarette outside a London nightclub in the early hours of Thursday morning as players wound down following Arsenal's 2-0 win over Napoli earlier in the week, when the 21-year-old had started on the bench.
The England midfielder's representatives maintained Wilshere was taking part in a "prank" where he agreed to hold the cigarette as part of a "dare", stressing he was "utterly committed to fitness and a healthy lifestyle". The player himself on Friday afternoon responded by posting a photograph on his official Twitter feed of France World Cup winner Zinedine Zidane smoking, which he then followed it up by saying: "But for the record....I don't smoke!".
Wenger, whose side head to West Brom on Sunday looking to maintain their place at the top of the Premier League, spoke out against the health issues of smoking in his pre-match press conference, and said he would to take up the issue directly with the player.
While Wilshere will have been left in no doubt as to what is expected from his future conduct, Wenger moved to quash suggestions the combative midfielder, who has battled through a number of injury problems in recent seasons, was now on the periphery following the fine start to the new campaign by Wales international Aaron Ramsey and the club-record £43million signing of Mesut Ozil.
"I told you Jack is an important player for the squad, and he will play, but there is competition for places of course. On one side, people want you to have good players, on the other, that means you cannot give any guarantee to anybody," said Wenger, who revealed full-back Bacary Sagna was set for around three weeks on the sidelines because of a hamstring problem.
"Higher up, he is less comfortable at the moment. He does not like to be back to goal, he likes to face the game. Why? Because he has a burst to pass people with the ball at his feet.
"From deep he does that very well, he creates the openings for that little burst to run with the ball. He is a physically strong boy he has a good body. He can win the challenge and make the difference and open the game up.
"He is getting it (his burst) back. I think to play on the flanks helps him to find that back, because on the flanks you have to do a lot of that."
England manager Roy Hodgson has again called Wishere into his squad for the crucial World Cup qualifiers against Montenegro and Poland.
Wenger has no doubts the Arsenal man can make a major impact at Wembley, despite making headlines for the wrong reasons this week.
"Even with one cigarette, he will be good," the Gunners boss said.
Wilshere has welcomed the competition for places in Arsenal's dynamic midfield, with Czech playmaker Tomas Rosicky starting against Napoli on his comeback from an injury lay-off.
With Theo Walcott and Santi Cazorla expected to be in contention after the internationals, and the likes of Yaya Sanogo, Lukas Podolski and Alex Oxlade-Chamberlain all now well on the comeback trail, Wenger accepts he could soon have some welcome selection headaches.
"That is part of our job to make unpopular decisions," he said. "No matter what happens you have 25 players. Whether the players well known or not, only the 11 players who start are happy and it is part of our job to cope with that."