William Gallas is in trouble after being photographed coming out of a nightclub with a cigarette in his mouth in the early hours of Thursday morning. The Arsenal captain is set to return from a thigh injury against West Ham United at Upton Park tomorrow, but he will play only after Arsène Wenger has investigated the incident.

“I don't like that,” the Arsenal manager said. “He has a responsibility as captain of Arsenal football club. That cannot be accepted.”

Arsenal have a strict disciplinary code and Wenger may choose to fine Gallas, although there is some confusion as to whether the cigarette was lit when the France defender was photographed getting into his car after leaving the reopening of the Movida nightclub in Central London.

Gallas was joined at the club by several Chelsea players, including Florent Malouda and John-Obi Mikel, who were celebrating their Champions League victory over AS Roma.

“In France we all smoke,” Wenger said, after admitting that he used to enjoy the occasional puff before he moved to England. “I've been on buses in France where you couldn't see each other because of the smoke.

“When I was a player nobody would ever tell you that you should not smoke. When I was a young coach I would have one because my assistant would have one. At three o'clock in the morning when we had lost a big game we'd have a smoke.” Wenger urged Arsenal supporters at the club's annual meeting on Thursday to turn up the volume and back their young side and the Arsenal manager will get the chance to see if his words have had any effect tomorrow.

“It was not a complaint,” Wenger said. “I do not want to go overboard. I want to convince more than complain, to convince our supporters that they can be proud of the team and that there are plenty of reasons to be an optimist with the quality that we have, with the structure of the club and the team.”

Arsenal need to win at Upton Park to stay in touch with the leaders after unexpected defeats against Fulham and Hull City. Wenger is looking forward to pitting his wits against Gianfranco Zola for the first time since the former Chelsea forward became the West Ham manager.

“He was an Arsenal-type player, but he went in the wrong direction,” Wenger joked. “We had Dennis Bergkamp and we had Kanu and we had Robert Pires. Zola had a team mentality as well, he wasn't only a star player.”

Matthew Upson, the England defender, who Wenger bought for £2million from Luton Town in 1997 before selling him to Birmingham City, is expected to start for West Ham. “He is a player I would have loved to hang on to but you have to play them or let them go,” Wenger said. “What is important is that he makes a career and I am happy that he has made a fantastic career.”