Fenerbahce boss Dick Advocaat has claimed that Manchester United fans have nothing to worry about with Jose Mourinho at the helm, but they must accept that he is "not a magician".
The Portuguese coach, who was sacked by Chelsea last December, was appointed as Louis van Gaal's successor at Old Trafford in the summer.
United have struggled for consistency of late having recorded just two wins in their last six games in all competitions, and they currently sit eighth in the Premier League table, eight points adrift of the top three.
Advocaat, who has previously managed Sunderland, believes that United will get back to winning ways because they have a successful coach and quality within the team.
"This man proved himself in all countries with the prizes he has won and it's quite unbelievable, but he is not a magician," Advocaat told reporters. "There are so many good players at United, but it makes it difficult to find the right lineup. Is it Anthony Martial, Marcus Rashford, Wayne Rooney?
"But it's only a matter of time, he knows that. I am sure United will play for first place in the Premier League and they will start winning games.
"Zlatan Ibrahimovic will start scoring, because this man knows how to score goals. They had so many chances last Saturday [against Burnley], it's unbelievable they didn't score. There is no reason to be worried about the team and the manager."
United earned a convincing 4-1 triumph over Fenerbahce in their Europa League group match at Old Trafford a fortnight ago.
The Turkish side will look for revenge on Thursday night when they welcome the Red Devils to Istanbul.
