Arsenal boss Arsene Wenger says midfielder Mathieu Flamini has suffered a hamstring injury against Leicester City.
The Frenchman was replaced in the first half of the game and will be assessed on Sunday to understand for how long he will be out of action.
Francis Coquelin should be fit to face Olympiakos in the Champions League with defender Gabriel Paulista back from suspension.
"Knowing that Tottenham has beaten Manchester City today it makes the whole league tight," he said.
"Two weeks ago you had Manchester City playing West Ham at home so you would expect that they would make the difference.
"[Injuries? Francis] Coquelin could be available for Tuesday. Today we lost Mathieu Flamini [because of a] hamstring [injury] and the only one that could come back is Coquelin and Gabriel is not suspended."
