Central defender Diego Godin has been left out of Uruguay's lineup for the World Cup quarter-final against Ghana after injuring his thigh in the second-round win over South Korea.
Uruguay coach Oscar Tabarez announced the starting lineup Wednesday, selecting Mauricio Victorino to replace Godin in one of two changes.
Godin "has not given total assurances that he'd be able to give everything during a game," Tabarez said. "He's not training with the team because I don't think he's 100 per cent."
Tabarez said he will also make a tactical switch and bring in midfielder Alvaro Fernandez to replace Alvaro Pereira.
The winner of Friday's quarter-final match will play either Brazil or the Netherlands in the semifinals.
Fernandez has been brought into the side in a move designed to help the Uruguayans maintain possession better than in the 2-1 win over South Korea.
Tabarez wouldn't give any further insight into the team's strategy.
"I talk tactics with the players," he said. "You'll see during the game how Alvaro Fernandez will be playing."
Fernandez, who plays for Universidad de Chile, admitted to being pleasantly surprised by the call-up.
"Being in the first eleven at a World Cup is the moment all players wait for," said Fernandez. "It took me a little by surprise."