Bale has played in three of a possible seven games for Madrid since his world record 100 million euro transfer from Tottenham at the close of this summer's transfer window.
Ancelotti said defender Raphael Varane will not play on Saturday due to injury while striker Karim Benzema was doubtful after picking up a knock during training.
Ancelotti also said he “needs to talk” with Iker Casillas after the Spain goalkeeper said he may consider leaving in the January transfer market if he doesn't play more.
“Casillas is a great goalkeeper,” Ancelotti said. “In the future I hope he will be here because he is an important player for the team's spirit.”
Casillas lost his starting job last season under former coach Jose Mourinho. Ancelotti has limited him to playing in the Champions League while Diego Lopez plays in the Spanish league.
