Roberto Martinez has confirmed that Bryan Oviedo suffered a fractured metatarsal in training and will miss the remainder of the Premier League campaign.
The Costa Rica international has endured lengthy spells on the sidelines since breaking his leg in two places against Stevenage in January 2014, with other injuries restricting him to just 11 appearances this season.
Martinez said: "We had a real disappointing situation with Bryan Oviedo in training, he's fractured his fifth metatarsal, which is incredible bad luck.
"He was in a great moment of form to get back in the squad and get back playing, but it was a very unfortunate action and he's going to be out for the rest of the season.
"He was trying to get on the ball and his ankle rolled a in a very awkward position. It's not his leg he had a breakage, it's the other."
The Everton manager hailed Oviedo's mental toughness in the face of such misfortune.
"It's given us a lesson in the mental strength he has," Martinez added. "We were really down for him and gutted and he's the one who's leading the rehab and is ready just to count the days down until he can come back.
"He's an incredible example of mental strength."
The injury also rules Oviedo out of his country's Gold Cup campaign, Martinez said.
