John Stones is likely to be sidelined until 2015 after Everton manager Roberto Martinez revealed he needs an operation on damaged ankle ligaments.
England defender Stones left Old Trafford on crutches on Sunday following the 2-1 defeat against Manchester United after he was stretchered off in injury time.
The 20-year-old was subsequently replaced in the England squad by Arsenal's Calum Chambers for the Euro 2016 qualifiers against San Marino and Estonia.
The club said via their official Twitter account that Stones is expected to be out until close to the New Year.
INJURY UPDATE: Martinez reveals John Stones' injury requires surgery and expects the defender to be out for 10-14 weeks. More to follow.
- Everton (@Everton) October 9, 2014
Stones joins Everton's lengthy injury list, with Sylvain Distin, Seamus Coleman, James McCarthy and Ross Barkley already sidelined.