The North London club's injury situation is worse than first feared with defender William Gallas, forward Eduardo and goalkeeper Manuel Almunia all out of Wedensday's match.
Wenger was already resigned to losing forward Andrei Arshavin and midfielder Alex Song.
"It's not a serious concern. The concern is that the players that are here perform at their best tomorrow. It's part of a season. We don't always have all the players available to select (for) the team but I'm not bothered by that," he told reporters.
Wenger added that defender Sol Campbell could feature in what would be his first appearance in the competition since he scored in the 2006 final which Arsenal lost to Barcelona.
"I haven't decided yet if he will start the game or not but if he plays his experience will be valuable," Wenger said.
The Frenchman also gave Polish goalkeeper Lukasz Fabianski, who is set to replace Almunia, a vote of confidence.
"I have great belief in Fabianski. I believe he is top level, and it is not easy for a goalkeeper to come in and out, but above all he has massive potential and at the moment what he misses is the number of games," he said.
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