Mikel Merino will undergo surgery on a bone injury in his right foot in the coming days, Arsenal have confirmed.
A club statement read: "Mikel will have surgery in the coming days and will then begin his recovery and rehabilitation programme.
"Mikel is expected to be out of action for an extended period, with the aim of returning to full training before the end of the season.
"Everyone is fully focused on supporting Mikel to ensure he is back to full fitness as soon as possible."
Reports have claimed Arsenal could enter the loan market after Merino's injury, but the transfer window closes at 7pm on Monday.
In terms of midfield cover, Arsenal have Declan Rice, Christian Norgaard, Martin Zubimendi, Eberechi Eze, Myles Lewis-Skelly and Kai Havertz as options, although Ethan Nwaneri has departed on loan to Marseille.
Merino has made 33 appearances in all competitions for Arsenal this season, scoring six goals and providing three assists.
He said on Instagram: "Time to stop now with a foot injury. Sometimes life throws this kind of challenges when is less convenient. Just another opportunity to be strong, resilient and overcome it. We have the best medical team and together we will come back stronger.
"Thank you all, your support means everything to me and I can't wait to be back on the pitch soon, helping my team and doing what I love."
Your Site' Nick Wright:
Merino has only started around half of Arsenal's games this season but his injury is still a significant blow to Mikel Arteta.
Versatile and tactically intelligent, he is an invaluable squad player capable of slotting into different roles. And while he has mostly played in midfield in recent months, his goal against Manchester United last weekend was a reminder of his striking instincts.
In fact, having filled in impressively as a makeshift striker, the 28-year-old ranks as Arsenal's second-most efficient attacker.
With 11 goals and five assists in 2580 Premier League minutes since the start of last season, Merino's average of 0.56 goal involvements per 90 puts behind only Bukayo Saka, on 0.63, among Arsenal team-mates in the same timeframe.
Another body may now be needed before Monday's deadline, even with Havertz available again following his return to fitness. But replacing everything Merino gives them will not be straightforward.
