Aaron Ramsey is likely to be out for six to eight weeks with the injury he sustained against Tottenham Hotspur on Saturday.
The Wales midfielder limped off with an injury to his left hamstring and Arsenal initially hoped he would be absent for just a month. But The Independent has learned he is likely to be out for closer to two months.
Last season Ramsey injured his left thigh muscle during a game with West Ham on Boxing Day. Manager Arsène Wenger expected he would be back within three weeks but he did not play for another three months.
Uefa has opened disciplinary proceedings against Arsenal and Galatasaray, as well as Basel and Borussia Dortmund, over crowd disturbances during Wednesday’s Champions League ties.
Several flares were thrown on to the Emirates pitch by Galatasaray supporters. Two fans were arrested for entering the ground with flares.