Mesut Ozil has been ruled out of Arsenal's Champions League showdown with Bayern Munich on Wednesday (7 March).
Ozil, 28, missed Saturday's Premier League defeat to Liverpool with the club confirming prior to kick-off he had been left in London to recover from illness.
Arsenal welcome Bayern to the Emirates on Tuesday needing a full-blown miracle if they want to keep their Champions League hopes alive; trailing 5-1 to the German champions after the first leg of their last 16 tie.
Germany international Ozil returned to full-training on Monday ahead of that game but given his lack of preparation, Wenger says he will not be calling upon the playmaker.
"He [Ozil] is not in the squad, he had just one training session yesterday," Wenger told a press conference on Monday. "I don't think he is ready for the squad. He should be ok for the weekend."
In other team news, Wenger says he has not yet decided whether Alexis Sanchez will return to his starting XI for Tuesday's tie. The Chile international started on the substitutes' bench on Saturday against Liverpool, with the Gunners falling two goals behind before half-time.
Sanchez was brought on at half-time and had an immediate impact, providing the assist for Danny Welbeck's goal before Liverpool scored a late third on the counterattack to seal the win.
Wenger's decision to drop the Chilean was roundly questioned ahead of kick-off on Saturday and even more so after the final whistle given the forward's second-half contribution. But when asked if Sanchez will be back against Bayern, Wenger said: "I haven't decided yet. We will see, I think I will make a decision tomorrow morning."
Arsenal also remain without midfielder Mohamed Elneny who has been ruled out for three weeks due to an ankle problem suffered in the FA Cup victory over Sutton United. Santi Cazorla also remains a long-term absentee. The Spain international underwent surgery to address an Achilles problem in December, but recently revealed he was forced to undergo another minor procedure with a time frame in place for his return.