Ancelotti confirmed on Saturday afternoon that Bale would be absent for the Athletic Bilbao match - but believes he will be fit for the Copa del Rey semi-final showdown with Atletico in midweek.
"He's not available because he didn't train throughout the week with the squad," said Ancelotti.
"He's done a good job today, he'll train tomorrow and I think he'll be available for Wednesday."
With the Wales International absent, former Academy player Jese - who stood in for Bale and scored the winner against Espanyol - could again feature.
Ancelotti said: "We have two options to replace Bale: Jese, who is doing very well and who we have a lot of confidence in, or (Angel) Di Maria on the right and (Asier) Illarramendi in the middle."