Pierre-Emerick Aubameyang is a doubt for Arsenal's clash with Leicester this weekend.
The Gunners striker sat out the midweek defeat to Wolves with a sinus problem but it was hoped he would be fit to return at the King Power.
Arsenal have confirmed Aubameyang underwent a small procedure on the issue this week and will be assessed ahead of the clash with Leicester.
Unai Emery's men have slipped down to fifth in the Premier League table after losing their last two matches to Crystal Palace and Wolves.
Aaron Ramsey has missed both those matches with a hamstring injury and will not be available on Sunday.
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The Wales midfielder continues to receive treatment on the problem and it remains to be seen if he will recover in time to play again for the club.
Barcelona loanee Denis Suarez will also miss the clash at Leicester as he recovers from a groin injury.
Arsenal face a crunch week in their attempts to secure Champions League football this season.
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Emery's men sit fifth in the Premier League ahead of this weekend's matches, although top four rivals Chelsea and Manchester United play each other on Sunday.
The Gunners play the first leg of their Europa League semi-final against Valencia on Thursday night before hosting struggling Brighton next weekend.
"We lost from our hands the opportunity for fourth, but we can also recover this opportunity," boss Emery said.
"The last three matches we play in the Premier League we have opportunities.
"Generally we are disappointed but we need to look at all the season. We need to prepare as best as possible for Leicester . Again it is very difficult but hopefully we can take something."
