Arsenal boss Arsene Wenger may leave out Alexis Sanchez for their FA Cup tie against Middlesbrough.
Wenger admits he has injury concerns for the Chilean.
"He didn't look right on Tuesday night. He got a knock on his knee and he was not feeling himself like he was before. There was not the same intensity as before.
"It is (a concern). He wants so much to play. But he still has a problem. It is muscular and should not be a problem. But if he is not available for Sunday he should be okay for the next game.
"If there is any medical risk he will not play. He is the type that you have to hold back. At the moment he has not been out on the pitch but if there is no medical risk I might play him."
