Midfielder Cesc Fabregas and striker Roberto Soldado are both doubts for Spain's Confederations Cup semi-final against Italy due to muscle injuries, the Spanish Football Federation (RFEF) revealed on Monday.
Fabregas was substituted in the 54th minute of Spain's 3-0 win over Nigeria in Fortaleza on Sunday, while Soldado went off six minutes later.
"Cesc and Soldado were last night submitted for MRI scans to evaluate the muscular pains that they finished the Spain-Nigeria game with yesterday," the RFEF said in a statement.
"In view of the test results, neither player's presence has been ruled out for the semi-finals, although their participation will depend on the evolution of the said pains."
Speaking after the Nigeria game, Spain coach Vicente del Bosque had expressed optimism over Fabregas' fitness.
"I guess something happened, he felt a slight pain, and he withdrew to be on the safe side," Del Bosque said.
"Now it's up to the doctors to assess what it is. It doesn't seem to be anything serious, but we're just being cautious."
Spain and Italy will lock horns at Fortaleza's Estadio Castelao on Thursday afternoon in a repeat of the Euro 2012 final, which Spain won 4-0.
Italy have several injury problems of their own ahead of the game.
AC Milan team-mates Mario Balotelli (thigh) and Ignazio Abate (dislocated shoulder) have both been ruled out of the tournament, while there are doubts over midfielders Andrea Pirlo (calf) and Riccardo Montolivo (nausea).