Fabio Cannavaro dismissed Sepp Blatter's slavery comments, saying Cristiano Ronaldo "must respect" his current contract.

Last week, FIFA president Blatter voiced his controversial comments on 'modern slavery' in football.

Speaking of United winger Ronaldo's future, amid public interest from Real Madrid, Blatter said that no player should be held against his will.

Real defender Cannavaro, though, feels players should honour their deals - with Ronaldo's current contract due to expire in 2012.

"Slavery is a big word," the Italian centre-back told La Gazzetta dello Sport. "Someone who signs a contract must respect it."

On Sunday, it was announced that Ronaldo is facing at least three months on the sidelines following ankle surgery.

The 23-year-old's future at Old Trafford still remains uncertain, with the Portugal international yet to confirm where he intends to play his football next season.