United are currently on a 20-match unbeaten run, and sit sixth in the Premier League table, but Mourinho continues to face criticism for a side that is seen to be underperforming given the club's lavish spending ahead of the season.

Ibrahimovic, however, believes the former Chelsea boss is overachieving given the circumstances, and has a "winning mentality" that will eventually filter through the whole squad.

"I think the coach is doing the absolute maximum with the team he has. 200 percent," Ibrahimovic told the Mail.

"If we were good enough to be No. 1, we would be No. 1 in the table.

"He still has the same winning mentality, because that you don't lose.

"When you have it, you have it. It is nothing you learn or can try to be. Either you are, or you are not."

Ibrahimovic, who is yet to pen an extension to his contract that ends in June, insists that although Mourinho's personality may seem brash, it's his straight talking that makes their partnership work best.

"I know him very well. He is direct in his work," Ibrahimovic added. "He likes to look into your eyes and tell you if you're s--- or not. I prefer that.

"He sends you the message he is thinking and he is the boss, he decides and controls the situation. It is the way it works and I am from the old generation, which I think was more like that.

"At half-time against Everton he told us we were not good enough. We should hear it because we were not."