Arsenal will be without a number of senior players when they visit Belgian side Standard Liege in their final Europa League group match on Thursday. Defender Kieran Tierney faces a considerable time on the sidelines after dislocating his right shoulder during the win at West Ham United. Reports suggested the Scotland international could be out for three months if he undergoes surgery. Arsenal can qualify for the last 32 with a win or draw. Other senior members of the team are also unavailable. Arsenal said Granit Xhaka suffered a concussion after being struck on the head by a ball from close range. The midfielder will miss Thursday's match and Sunday's Premier League clash to Manchester City. Nicolas Pepe will miss the Liege match after he bruised his knee, while Hector Bellerin is suffering from a tight hamstring. Dani Ceballos and Rob Holding remain sidelined. Amid all these injury news, Arsenal trained on Wednesday. Interim coach Freddie Ljungberg will now be looking over his shoulder as Carlo Ancelotti has become available. Above is a picture gallery of the training session. To move on to the next image, click on the arrows, or if using a mobile device, simply swipe.