Alexis Sanchez and Santi Cazorla are reportedly expected to miss Arsenal's must-win Champions League match against Olympiacos next week.
Both players picked up injuries during the Gunners' 1-1 draw against Norwich City on Sunday.
Manager Arsene Wenger has been criticised for playing Sanchez at Carrow Road as he was already carrying a slight hamstring strain.
According to The Mirror, Sanchez is expected to be on the sidelines for three weeks, while Cazorla is also on the treatment table, with both players expected to miss the match in Greece, where Arsenal need to win by two goals to qualify for the last 16 of the European competition.
Meanwhile, reports have claimed that Laurent Koscielny should be fit, despite suffering a hip problem during Sunday's fixture.
Arsenal will face Sunderland in the Premier League this weekend prior to their Champions League showdown on December 9.