Deco is blown away by Cristiano Ronaldo's dedication to being the best player possible.

"The guy is sick, I haven't seen anyone in training sessions like that. I think it's really difficult to be like that," Deco told ESPN Brasil.

"They are completely different. Though Messi takes care of himself like a normal athlete, Ronaldo is unbelievable.

"It borders on sickness because he always wants to be the best at his job. He competes in everything.

"I think it's great to see both players in action, it's almost impossible to compare them.

"If you look at one's game it's totally different from the other's. There are no parameters for comparison."