The Wales winger was included in the squad for the game at the Bernabeu after missing Real's last two matches and coach Carlo Ancelotti said on Tuesday he would be available.
Cadena Ser, without identifying the source of its information, said Bale had not shaken off the injury and had been released from the squad.
A Real spokeswoman could not immediately confirm the report.
Bale's debut season in Spain has been disrupted by a series of minor injuries after the 24-year-old joined from Tottenham Hotspur for a world record fee of 100 million euros ($135 million).
($1 = 0.7390 euros)
- Sports & Recreation
- Carlo Ancelotti