Everton defender John Stones could be sidelined for about four months after the Premier League club announced that he needed an ankle surgery.
The 20-year-old was carried off the pitch on a stretcher during Everton’s defeat at Manchester United on Sunday.
Stones has since withdrew from the England squad for the Euro 2016 qualifiers against San Marino and Estonia this week.
He has been told the injury requires an operation and will likely not be able to kick the ball until 2015 at the earliest.
“John will need surgery, which will give us a perfect recovery for his left ankle,” Martinez explained. “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 joins centre-half Sylvian Distin, full-back Seamus Coleman, midfielders James McCarthy and Ross Barkley and forward Kevin Miralas on the treatment table at Goodison Park at the moment.