Gervinho's ankle injury will keep him out of action for three weeks, Arsene Wenger has confirmed.
The Arsenal forward turned his ankle during a brief substitute appearance against QPR last weekend.
And at his press conference ahead of the weekend trip to Manchester United, Gunners boss Wenger revealed the Ivory Coast international will be out for most of November.
That means the 25-year-old is likely to miss the return UEFA Champions League game with Schalke and London derbies with Fulham and Tottenham.
The injury deprives Wenger of his top Premier League scorer - three of Gervinho's five goals this season have come in the league.
And Arsenal will still be without goalkeeper Wojciech Szczesny, left-back Kieran Gibbs and midfielder Abou Diaby at Old Trafford.