Ronaldo is back at Old Trafford for the first time since leaving United five years ago.
"I think he'll have a great reception but once the kick-off happens he'll forget about all that and I don't think it will affect his performance. I prefer to have him on my side. He's in terrific form and I know that he is looking forward to playing against his former team. If we play well we'll have more of a chance to win, but if we don't defend well they can score as well," said Xabi.