Nacho Monreal could be sidelined for the next four Arsenal matches with an inflamed back injury, Arsene Wenger has revealed.
The Spain international was forced off the field in the first half of the 3-0 Carabao Cup final defeat to Manchester City on Sunday.
Monreal will be a certain absentee when Arsenal meet City for the second time this week on Thursday, live on Sky Sports Premier League, and for Sunday's meeting with Brighton, also live on Sky Sports.
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"He is out for the two games this weekend - Thursday and Sunday certainly. He might be out for two more games - Milan and maybe one more [Watford]," Wenger said at his pre-match press conference.
"He has an inflamed back."
Arsenal, who lie in sixth spot in the table, are 10 points off the top four and qualification for the Champions League which means realistically the Europa League offers the north London club their best route to a return to Europe's top club competition.
After taking on Brighton the Gunners will travel to Milan to face the Serie A club at the San Siro for the first leg of their last-16 tie before returning to domestic action against Watford on March 11, live on Sky Sports Premier League.