Arsenal manager Mikel Arteta has confirmed that Fabio Vieira is expected to be out for weeks after undergoing groin surgery.
Vieira was absent in training ahead of their Champions League clash with Lens on Wednesday.
Arteta has now revealed the 23-year-old is now facing time out on the sidelines.
The Portugal midfielder missed Arsenal’s Premier League clash with Brentford at the weekend due to suspension but was expected to return against Lens.
“We’ve got a problem with him. He’s been having some discomfort,” Arteta told reporters.
“He wasn’t improving and we sent him to a specialist; the advice was to have an operation, which we did yesterday. We expect him to be out for weeks now.”