Pogba returned to Old Trafford from Juventus last August for an initial fee reported to be £89.3 million ($155.92 million), one that eclipsed the £86 million ($150.16 million) Real Madrid paid for Gareth Bale in 2013.
The France international has struggled to live up to that sizeable investment in his first season back in English football, with the 24-year-old often accused of trying too hard to impress during an inconsistent campaign on the whole for the club.
Mourinho insists Pogba has performed well, particularly in United's run to the UEFA Europa League final, but hopes to see another player become the most expensive in the world so as to alleviate the pressure on the midfielder's shoulders.
He told Omnisport: "I think the problem is the tag, the price tag on his back. I hope next summer he's not anymore the highest transfer fee and then the pressure goes to somebody else.
"If his transfer fee was half of it, everybody would say 'what a buy,' 'he's playing more than good'. But everybody expects performances according to that huge transfer fee and that brings pressure and that brings sometimes unfair analysis.
"He had very good matches, he had very good performances. He always sacrifices for the team. If I go for example to Rostov, the way he played in Rostov was amazing. He had little matches where the performance was not so good but normally the performance is related to the team. So when the team was very good, he was very good. When the team didn't perform so well, he didn't perform so well.
"So I think it's a bit unfair. I hope next season some club beats the record with another player and then the pressure goes somewhere else."
Mourinho is confident that Pogba can become the world's finest player in his position if he continues to develop at United.
"I never liked too much 'the best in the world' – you never say the goalkeeper is 'the best in the world', you only say [Fabio] Cannavaro if somebody decided to say a central defender is the best in the world. The best in the world is almost always the goalscorer. It's a bit unfair," he said.
"So to say the best in the world is difficult to say. I think to be the best midfield player, I think so. I don't see another one with everything he has. He has to develop; of course he has to develop. But he has the physicality, he has the brain, he's very skilful, he's very agile for that huge body he has.
"He's good in the air defensively, attacking ... He's a very good free-kick taker, so if Zlatan [Ibrahimovic] gives him permission to take more, he would score a few goals. I think he has everything."
One player who has thrived at United this season is Zlatan Ibrahimovic, who struck 28 goals in all competitions in his first season in English football before a serious knee injury sustained last month ended his campaign.
Club captain Wayne Rooney has however found life difficult this term, having struggled to force his way into Mourinho's first-team plans despite United's huge number of matches.
Mourinho accepts that it can be difficult for top players to handle such a situation during the closing stages of their career but he hailed Rooney's dedication throughout the campaign.
"It's very difficult because during my career I had this kind of situations of getting players – amazing players with amazing history – in the last period of their career," he said.
"When you get players in the last part of their careers, the players with the big history in the club – and I had that everywhere, I had that in Inter, I had that at Real Madrid, I had that at Chelsea.
"Frank Lampard, Didier Drogba, to have them – and in my case I had them in the best period of their career – and then when I returned the second time, I had them in their last period of their career. How difficult it is.
"And sometimes, the players understand the situation. Sometimes the players still feel they are 24, 25 and it's very difficult. The good thing with Wayne is that he's a very club man. He's very club man. And if he is frustrated, he hides it. If he is not happy, he hides it. He behaves in the best possible way. And when he's not injured, he's always available. And in fact now, I need him. I need him back because we have so many problems."