Spain and Barcelona face a nervous wait over the fitness of Victor Valdes after he sustained a calf injury during La Roja's shock 1-0 friendly defeat to South Africa on Tuesday.
Valdes replaced Iker Casillas at half-time but was then forced off with 13 minutes remaining after complaining of a strain in his right calf.
The Barca goalkeeper will undergo tests when he returns to his club on Wednesday, although the early diagnosis suggests he suffered a tear.
A medical statement on the Spanish football federation's website read: "Victor Valdes, possible calf tear of the right leg. This Wednesday he will have new tests at his club to determine the exact extent of the injury. The national team doctors treated the goalkeeper immediately after he retired from the game in the 77th minute.
"They have determined that he could have suffered a torn calf in the right leg. Valdes was injured after going to clear the ball in a dangerous South Africa counter-attack."
Spain coach Vicente Del Bosque was pleased with his side's performance but admitted South Africa were worthy winners.
"Maybe we deserved defeat," he said. "We came out with good intentions and we fought right until the end. I can't have any complaints about our efforts, but they worked a bit harder and were a bit better than us tonight."