Samir Nasri has suffered a broken leg during pre-season training in Austria.
The France international is going to be out for two to three months after fracturing his right fibula.
Nasri will miss the opening few weeks of the Premier League season.
The 22-year-old suffered the injury during a training match and was taken to a nearby hospital.
A statement on the club’s official website confirmed:
“Samir Nasri has sustained a fractured fibula during this morning’s training session at the club’s pre-season training camp in Austria.
“The midfielder will be out of action for two to three months.”