Manchester City winger Leroy Sane will undergo surgery in the next few days after tearing his cruciate ligament in the Community Shield win over Liverpool.
The 23-year-old German international went off clutching his right knee after just 13 minutes at Wembley.
Sane, who has been linked with a move to Bayern Munich this summer, is now expected to remain at City.
City begin the defence of their title at West Ham at 12:30 BST on Saturday.
A statement on the club's website said: "He [Sane] has undergone testing throughout the week, with a specialist doctor travelling to Manchester for further examinations to understand the extent of the injury.
"Manchester City will provide Leroy with all the support and guidance he needs, and everyone connected with the club wishes him a quick and full recovery."