Real Madrid legend Zinedine Zidane has labeled Cristiano Ronaldo an "alien" and warned his club of Champions League opponents Schalke.
View: Gallery: Ronaldo Goes Missing As Atleti Thrash Real
The 1998 World Cup winner, who now coaches Real's B-side (Castilla), also insisted the Portuguese fully deserved his third Ballon d'Or title ahead of Bayern goalkeeper Manuel Neuer.
"Neuer is a fantastic player, who lifted the keeper's game to a new level," the Frenchman told Welt am Sonntag.
"He is a phenomenon between the posts.
"But at the same time, Ronaldo is from a different planet. He is like an alien. What he does is unique."
Real Madrid's form hit a new low this weekend when they lost 4-0 to Atletico Madrid, and Zidane warned his side of the Champions League last-16 clash with Schalke.
"I would love to say Schalke have no chance and Real are already safely in the quarter-finals," he added.
"But, especially in the knockout stage, anything can happen.
"In two matches there is always a chance the underdog will rise. You have to be careful, especially against a German team."
Read: Ronaldo: We Should Never Lose 4-0 To Anyone
Ronaldo is still the leading goalscorer in Spain, but started 2015 with only four goals in seven games.
Do you think Cristiano Ronaldo plays like he is from another planet? Have your say in the comments section below.
