The Red Devils have come up short in the Premier League this season, with Manchester City having run away with the title following their brilliant form under Pep Guardiola in his second season in charge.
Nevertheless, Manchester United are on course for their highest placed finish since Sir Alex Ferguson’s retirement, and they can still win the FA Cup by beating Chelsea FC in the final later this month.
However, they are likely to be very active in the summer transfer window as Mourinho looks to assemble a squad capable of winning the Premier League title next season.
The Red Devils are bound to be linked with a host of players in the coming weeks and months as Mourinho looks to strengthen his squad.
And the Portuguese coach has conceded that the Red Devils are in need of some quality additions as the summer transfer window draws nearer.
Speaking at a news conference on Wednesday at Carrington, Mourinho said: “How many points separate us from Manchester City? Not two, three or four. A lot of points.
“I think we need both things [more quality and a better mindset] that you mentioned. Some of the people we have, they have to be more consistent in their performance and we need more quality.
“I trust some more than others that can bridge that gap. I worked with the players for a couple of years. I know them better than anyone.
“Of course, some of the players I am totally convinced are going to make it. Some others, I have good hopes that they are going to make it. And some others, I don’t believe they are going to make it.”
Manchester United have not won the Premier League title since Ferguson’s final season in charge back in 2013.
The Red Devils did win the Europa League and League Cup in Mourinho’s first campaign in charge last season.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news