Despite the arrival of the prolific forward, alongside world record-signing Paul Pogba, United have struggled to establish themselves among the league’s top-four and face the prospect of another season without Champions League football.
Their best hope of qualifying for Europe’s elite competition now rests in the Europa League.
And while United have only lost three games in the league this season, their 20-game unbeaten run has not been enough to lift them any higher than sixth because of a series of frustrating draws.
But Ibrahimovic has praised Mourinho for his work at Old Trafford and believes the manager is getting the ‘maximum’ out of his team.
"I think Mourinho is doing maximum with the team he has," said Ibrahimovic, who has scored a total of 27 goals in his first season in England. "Absolutely. He is getting 200 per cent out of the team he has.
"I know him very well from the past. I think he is older and he is calmer, but he is still the same winner as before.
"I mean the mentality is there because that you don't lose. When you have it, you have it. It is nothing you learn, it is nothing you try to be. Either you are or you are not a winner.
"That's why I think his season has been good. We have done a good season for the team we have. We have won two trophies and I think the coach is doing absolutely the maximum with the team.
"Of course, some games you are unlucky, some games you are lucky, some games you do mistakes, some games the mistakes can be accepted but you still get a win.
"This is part of the game. If we were good enough to be No 1, we would be No 1 in the table now. So we have to be realistic - and I think this season has been great."
Ibrahimovic is yet to confirm whether he will stay at United beyond his debut season but his renewed relationship with Mourinho, having worked together at Inter Milan before, is one he clearly enjoys.
The Swede added: "The manager likes to look you in your eyes and tell you...and I prefer that.
"He is direct and at least he sends you the message of what he thinks. He is the boss, he decides and he controls the situation.
"He told us at half-time against Everton that we were not good enough - and it was right that we heard that because we weren't good enough.
"It is the way it works. I am from the old generation and I think the old generation was more like that."