Hector Bellerin has undergone successful surgery following his anterior cruciate ligament injury, Arsenal have confirmed.
The full-back was stretchered off during the recent 2-0 win over Chelsea, his first start since injuring his left knee earlier in January, before being ruled out for the rest of the season.
Bellerin will now begin a recovery programme leaving Ainsley Maitland-Niles, Stephan Lichtsteiner and Carl Jenkinson to cover at right-back, after Unai Emery insisted the club would not need to sign a replacement this month.
After fears of a broken jaw sustained in the FA Cup defeat to Manchester United were allayed, Laurent Koscielny has this week returned to full training at London Colney, where the squad were joined by new signing Denis Suarez on Thursday.
Koscielny was rushed to hospital last week after taking a boot to the face in a tangle with Romelu Lukaku, though scans revealed he had merely suffered bruising and swelling.
Maitland-Niles continues to be assessed ahead of Sunday's trip to Manchester City, as does Henrikh Mkhitaryan foot concern.
Rob Holding and Danny Welbeck remain, alongside Bellerin, long-term absentees while Sokratis, another casualty of the United defeat, is expected to return to training next month.
