"Playing in Madrid is always difficult," he told reporters. "I think Madrid were strong last year, and they're just as strong this year.
"Maybe they've improved having brought in [Gareth] Bale, but coming here is always tough for teams. I think Ancelotti is one of the best coaches in Europe.
"He's a quiet man but a good person – a great coach. We know it's going to be tough here, but we're going into the game looking to play well and win."
Galatasaray and Copenhagen both have four points in the group, while Juventus are at the bottom with three.