Mesut Ozil will miss Arsenal's next few games for because of a hamstring injury suffered in Tuesday's Champions League game against Bayern Munich.
Arsenal tumbled out of the tournament after a 3-1 aggregate defeat, and the loss of Ozil will affect the team as they try to qualify for next year's Champions League.
Tomas Rosicky replaced Ozil at half-time on Tuesday, and after the match Arsenal manager Arsene Wenger confirmed a hamstring injury for the club-record signing.
"He has a hamstring problem that looks quite serious," Wenger said. "I don't know (how long he will be out for), but for sure he is out (of the Tottenham game on Sunday)."
Ozil had looked refreshed and scored in the 4-1 FA Cup quarterfinal win over Everton on Saturday, but now he could be set for a lengthy spell on the sidelines.
"We have to make a scan tomorrow to see how bad it is but he's out for at least a few weeks," Wenger said. "I hope it's not too bad."
Arsenal have several key matches to come in March. This weekend's North London derby followed by a trip to Premier League leaders Chelsea on March 22, while they also host Swansea City and title-chasing Manchester city before the month is out.