The Sun says the England midfielder, 19, will have an ankle op on Monday and has been warned he will not play until the New Year.
Wilshere has been wearing a protective boot due to the injury which has been troubling him for over a year. He broke down with the problem in the Emirates Cup and has yet to play this term.
A Gunners spokesman said: "We have given Jack time to heal naturally which is important wherever possible with a young player. The latest scans show surgery is needed.
"Everyone at the club wishes Jack a speedy recovery."