Arsenal manager Mikel Arteta has spoken about the injury sustained by winger Bukayo Saka.
The young English star, who was in outstanding form, came off against Lens in the Champions League with a hamstring problem.
Saka was a doubt for the game, with Arteta risking his youngster's fitness for the group stage game.
Speaking to TNT Sports, he said: "It wasn't an action, it was a back heel and he felt something and he wasn't comfortable to continue."
When talking to TV Sport 2 about the injury, Arteta added: "It doesn't look good."
The Gunners take on Manchester City in the Premier League at the weekend.