Real Madrid striker Ronaldo will be out of action for up to three weeks with a muscle tear in his right thigh, the Spanish Primera Liga club said on Monday.
The Brazil international scored his 100th goal for the club against Real Sociedad on Saturday, before limping off early in the second half. The game ended in a 1-1 draw.
After a season blighted by injury Ronaldo looked to be returning to form with Saturday's goal, his fourth in as many games, and with the World Cup on the horizon.
Being Real's leading scorer with 14 goals, Ronaldo will be sorely missed in the battle for second place in the league and direct qualification to the Champions League next season.
Barcelona lead the standings on 70 points with six games to go. Valencia are level with Real on 59 points, but second due to their superior head-to-head record. Osasuna are fourth with 58.