Bareira told Sky Sports: "I think without a doubt it will be a risky move, like it was when he came to Sporting, because right now he has two championships for Sporting.
"He's done good in the European competitions, he would have got the opportunity to play Manchester City on Tuesday. It was a risky move to get him into Sporting in the first place, but it was a good one because he won trophies."
He added: "I think he wants to be like Jose Mourinho, who is his idol, and he wants to win trophies with Manchester United."