The former West Germany defender says the young Brazilian will never become one of the world's best players unless he moves across the Atlantic
The Brazil international has been widely linked with a variety of the continent's top clubs and the former West Germany star believes he needs to make the move to take the next step.
“No one knows his true potential. He needs to play every day against players like [Franck] Ribery and Cristiano Ronaldo to know whether he's a true star or not,” Bretiner told ESPN Brasil.
“I'd like to see Neymar playing in Europe, because no one knows how good he is. Not even he knows that.
“Becoming a star only in Brazil is not enough. He needs to prove his class, his level, his skills, where the best football is being played at the moment, and that's in Europe.”
The 61-year-old cited Barcelona forward Lionel Messi as an example of a South American who took his career to the higher level by moving across the Atlantic Ocean.
“I find it funny when I read that he wants to be the best in the world playing here. Messi wouldn't have become the best player in the word if he had stayed in Argentina. And Neymar won't either."
Among the clubs linked closest with a move for Neymar are Bayern, Barcelona and Real Madrid.