The midfielder suffered the damage, which is very similar to Leighton Baines' from earlier this term, during the Toffees' FA Cup win over QPR and could now face up to six weeks out
Barkley sustained the injury in their 4-0 FA Cup win over QPR on January 4 and is almost certain to miss the Merseyside derby at Liverpool at the end of the month.
|25/1||Ross Barkley is 25/1 with Betway to make England's World Cup squad|
"It looks like he's going to be out for a while," Martinez told reporters.
"It could be [broken] and that's what we're worried about. It's a very similar incident to the one Leighton Baines had.
"Some can go a couple of weeks and others a bit longer like Leighton. Because it was a bad one it took six weeks."
Baines missed six games after picking up the same injury in the first Merseyside derby of the season at Goodison Park in November.