The Frenchman, who has scored two goals in three appearances so far this season, will miss this weekend’s Premier League clash against Watford at Vicarage Road.

Arsenal confirmed the news with an injury update on their official website shortly after head coach, Unai Emery, had spoken to the media on Friday.

“After assessments to an ongoing ankle issue, we have advised that Alex will need to rest and strengthen his ankle to regain full fitness.

“Alex has been playing through this injury for several weeks. He is likely to be back in action in October,” Arsenal said.

The forward, however, appears to be positive, despite the injury blow. He took to social media to say he had started rehab already.

“Already started my rehab and looking to the future,” he tweeted.

“Thanks everyone for your messages!!”

His injury is expected to leave Emery with some selection headache ahead of the game against Watford, as he has been instrumental for the club.