Arsenal defender Kieran Gibbs ruled out of Champions League tie against Besiktas

Gibbs injured his hamstring in Arsenal’s 2-1 win against Crystal Palace

Arsenal full-back Kieran Gibbs has been sidelined due to injury for the next three weeks and will, therefore, miss both the home and away leg of the Champions League (CL) playoff against Besiktas.

The 24-year-old injured his hamstring during Arsenal’s 2-1 win over Crystal Palace in their opening encounter of the 2014-15 Barclays Premier League (BPL) season on Saturday.

Centre-back Laurent Koscielny, who seemed to have injured his Achilles during the game, has recovered sufficiently and is available for selection for Tuesday’s game.

His compatriot Mathieu Flamini returns after missing the game against Palace, but striker Yaya Sanogo, who suffered a hamstring injury as well, has not travelled to Turkey.

Gibbs and Sanogo join Theo Walcott, Serge Gnabry (both knee) and David Ospina (thigh) in the injured list at Arsenal.

The German trio of Mesut Ozil, Per Mertesacker and Lukas Podolski, meanwhile, are still not ready for competitive action after returning to training at Arsenal just a week before the beginning of the Premier League campaign.

Arsenal need to get past Besiktas in the CL playoff in order to reach the group stages of the Champions League for the 17th consecutive season.