Arsenal will enter four of their biggest games this campaign without midfielder Mathieu Flamini.
The French international limped off in the Gunners' 2-0 victory at Crystal Palace at the weekend after just eight minutes with a groin injury.
He will now miss Arsenal's Capital One cup game at home to Chelsea and then miss the top of the table clash as The Gunners host second placed Liverpool.
Since re-signing Flamini on a free transfer from AC Milan, the midfielder has been a strong motive behind Arsenal's early season success.
He has offered protection to the back four, in particular centre backs Per Meresacker and Laurent Koscienly who were often hesitant and indecisive last year.
Arsenal will also be without the suspended Mikel Arteta for the Chelsea game through suspension however, will be available for the Liverpool game.
It is too likely Flamini will miss two of Arsenal's biggest away games.
They travel to Borussia Dortmund on November 6th in a must not-lose game if they want to qualify for the next round of the Champions League and that is followed four days later by a trip of Old Trafford against their old foes Manchester United.
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