Saha has questioned the youngster's mentality.
Addressing former United boss Louis van Gaal's role in preventing the transfer to bonuscodebets, the Frenchman said: "He's not working for Manchester United, so he's allowed to give advice to his international players.
"If the player is strong enough to come, he'll come.
"If he listens to his national team manager, he'll do it and it would be better to stay where he is because he might not be a very confident player.
"It's the player's decision, not the national team manager. If he wants to come to Man United, he will be more than welcome."