Everton midfielder Bryan Oviedo will miss the remaining four games of the season after fracturing a metatarsal in his right foot during training.
The Costa Rican, 25, had just recovered from a hamstring strain and was poised to play for the under-21s on Thursday.
Oviedo, who has only played 11 times this season, is expected to be unavailable to play for his country at the Gold Cup in Philadelphia this July.
Everton boss Roberto Martinez said: "He's fractured his fifth metatarsal."
Oviedo has suffered a number of injuries in the last 18 months, missing the 2014 World Cup after a double leg fracture in January 2014.
"He was in a great moment of form and looking forward to getting back into the squad and finishing the season playing," added Martinez.
"It was a very unfortunate action on his own and he is going to be out for the rest of the season. He was trying to get on the ball and his ankle rolled in a very awkward position."