Madrid - Real Madrid coach Julen Lopetegui has confirmed Gareth Bale sustained an injury to his thigh during the goalless draw with Atletico Madrid on Saturday.
Bale was substituted at half-time at the Santiago Bernabeu and is now a doubt for Real's Champions League game against CSKA Moscow on Tuesday.
"Gareth had discomfort in his thigh," Lopetegui said after the match.
"He came off as a precaution and we will see tomorrow what the injury is."
Bale has scored four goals in his last seven games for Real and any absence would be a major blow.
Real face Barcelona in La Liga on October 28 after league games against Alaves and Levante, as well as another Champions League group fixture at home to Viktoria Plzen.