Arsenal boss Mikel Arteta admits they need to wait on scans for Jurrien Timber.
Timber was forced off early in the second-half of victory over Nottingham Forest after a clash before halftime with Brennan Johnson.
"The doctors looked at him and they were happy for him to continue, he was as well," Arteta said in his post-match press conference.
"Straight away in the first action of the second half he made a movement and it was a bit funny.
"We took him out straight after and now we have to assess him and see what he has."