Arsenal manager Arsene Wenger says defender Mathieu Debuchy will be ruled out for at least three months.
The 29-year-old dislocated a shoulder during Arsenal's 3-0 win against Stoke, his second long-term injury this season after missing three months at the start of the season due to an ankle injury.
"Mathieu [Debuchy] had a surgery on his right shoulder following the injury on Sunday," Wenger told the club's official website.
"It's very unfortunate for Mathieu, it's unbelievable because he's had two surgeries in the same season. He just came back, he played seven games and he's out again.
"I count three months out for Mathieu because contact will be a problem for the shoulder."
Meanwhile, the Frenchman revealed Kieran Gibbs will resume training on Friday but striker Danny Welbeck will not be available for Sunday's away game against Manchester City.
"Kieran Gibbs will be training again with the squad on Friday and we will see how he goes from there. His news is positive," the 65-year-old added.
"Danny Welbeck is not ready yet, he is still feeling some pain, so we will have to be patient."
