Real head coach Ancelotti has been without the Portuguese star for his team's last three La Liga matches after he was shown a straight red card for an altercation with Athletic Bilbao's Carlos Gurpegui in a 1-1 draw on February 2.
Having had an initial appeal against the decision turned down by the Spanish Football Federation, Real took their case to the Ministry for Education, Culture and Sport, only for the government department to uphold the original ruling.
Ancelotti stated that Ronaldo was disappointed to have sat out three league matches, but is confident the 29-year-old can have a starring role in the last 16 first leg encounter at the Veltins-Arena on Wednesday.
"He's motivated because he is really looking forward to get back playing," the Italian said.
"He was not happy about not being able to play and he has prepared himself well for this game. Mentally and physically he is in optimum condition."
Ronaldo, who has scored nine goals in just five Champions League games this season, is expected for a form a front three with Karim Benzema and Gareth Bale in Germany, with Jese Rodriguez set to drop to the bench.
