But Blackburn boss Hughes has told Ronaldo he would be foolish to leave the Red Devils after quitting Old Trafford himself in 1986 for Barcelona, only to return two years later.
"I think the Premier League is the hardest league in world football and Ronaldo is playing with the top club in it," Hughes said in the Daily Star.
"Why would he leave it? There is absolutely no reason to do so because everything is there for him.
"He is a top player in the top club in the top league, so there is no reason to leave.
"Barcelona, for instance, is a fantastic club and has the standing in world football that United has.
"But I don't see Barca as a top club at the moment."