David Moyes said he is certain that Marouane Fellaini will become a success at Manchester United despite a difficult first four months.
• Mitten: Januzaj's meteoric rise
Midfielder Fellaini became the fourth most expensive player in United's history when he joined from Everton for 27.5 million pounds in the final hour of the summer transfer window.
But he is yet to score for his new club, has struggled to hold down a first place and was sent off in the Champions League draw away at Real Sociedad.
And Fellaini, who has also been struggling with a back injury, has been ruled out for six weeks after undergoing surgery on his wrist at the weekend.
But Moyes, who also managed the Belgium international for five years at Goodison Park, is tipping him to deliver the goods for his new club.
He said on Monday: "I have no doubt he will eventually be a good player for us. He has been unlucky. He has not felt 100 percent because of his wrist and has been finding it difficult.
"I asked him to see if he could get over the Christmas period. He got the back injury against Everton and since then he has never really been right."