The France international was thought to have damaged his ankle after scoring a late equaliser in Arsenal's 2-2 draw at Everton in the Premier League on Saturday, but Wenger revealed that he had in fact broken his leg.

"Giroud had surgery today for a broken tibia and he will be out for three to four months on the competitive side," Wenger told a press conference after his team beat Besiktas 1-0 to reach the Champions League group phase.

"He'll be capable to play again in the Premier League at the end of December. He'll be out for two months, but the time he needs to comes back, three to four months.

"You'll ask who we'll buy (to replace Giroud). At the moment, nobody."

In Giroud's absence, new signing Alexis Sanchez scored the only goal of the game at the Emirates Stadium to send Wenger's side into the Champions League group stage for the 17th successive season.