But Keane told Sky Sports: "I think he is a talented boy. But does he help people out and does he make others around him better?
"The answer is 100 per cent no. He does like to dig them out, which is fine, but you've also got to drag the others along.
"Would you like to be in that United dressing room today with these guys going... 'not sure about him, I think he's OK when we're winning but we're not going to be winning every time'.
"How do you stop that momentum and flex your muscles in games? That's what I want.
"We talk about talented players but sometimes it's about personalities in big games and getting you over the line in big games."
He added, "Look, he's won nothing in his career. He's won nothing in his career. Look at his CV. if he's one of your best players there's a responsibility."