Arsenal boss Unai Emery is unsure if Mesut Ozil will be fit to feature in the Premier League match against Manchester United on Wednesday.
Ozil, 30, suffered a back spasm in the days leading up to the north London derby and was not included in the squad that secured a thrilling 4-2 triumph over Tottenham.
The playmaker also missed last week's Europa League victory at Vorskla and remains in doubt for the trip to Old Trafford.
Speculation is beginning to swirl around Ozil's future with the Germany midfielder seemingly an awkward fit under Emery, who left him on the bench for the recent win away to Bournemouth.
"He's had a backache since last Tuesday. He couldn't play in Kiev or [on Sunday]," the Gunners boss said.
"At the moment, I don't know if he can play in Manchester.
"[On Monday] he was [training] alone, I don’t know if he's okay for Wednesday."
Arsenal, unbeaten in 19 matches in all competitions and having won four of six top-flight games on the road this term, appear to be catching United at just the right time.
United are winless in three Premier League outings following the 2-2 draw at struggling Southampton, although they have not lost a top-flight home fixture against the Gunners since 2006.
"It's a new match, a new challenge, a big challenge," Emery said.
"It's away and we need to continue improving our mentality away. We know we need to change to get more competitive away.
"I think the team is doing that, but it's a new challenge because we're going to play against Manchester United away, and the challenge is bigger than other matches.
"For us, it’s a very exciting match. The preparation for this match is also a big motivation for us. If we are stronger now, we need to [show that] on Wednesday."
