Everton defender John Stones is to undergo surgery on his ankle which will see him ruled out of action for up to 14 weeks.

The 20-year-old England international damaged the ligaments in his left ankle during the Toffees' 2-1 defeat against Manchester United last week.

Manager Roberto Martinez confirmed that Stones will need to undergo an operation to rectify the problem, which will likely see him ruled out of action for the remainder of the year.

"John will need surgery, which will give us a perfect recovery for his left ankle," he told the club's official website. "We expect him to be out for probably the next 10 to 14 weeks depending on how everything goes.

"It's a clear injury – not a complicated injury. Obviously, it's a little bit of a setback because you don't want to lose any players, but in John's case we were very worried in the moment that it happened because those injuries can become a little bit difficult to treat.

"But this one is going to be straightforward and we are already counting down the days for him to come back and we'll make sure he comes back stronger and ready for the final and most important part of the season."

Stones, who has been capped four times at international level, was replaced in the Three Lions squad by Calum Chambers earlier this week.