Mourinho was left frustrated yesterday as United failed to land any more signings, including the central defender he wanted.
Despite weeks of reported haggling over the potential signign of Harry Maguire from Leicester or Toby Alderweireld fro Tottenham, United ended up empty handed.
Although the Red Devils made three acquisitions, Mourinho has been at a stand-off with executive vice-chairman Ed Woodward over transfer business.
"I said that during pre-season - it looked like I was saying something absolutely out of order, it looked like I was saying something insane - but I repeat, pre-season is hard when you don't have your players to work with".
According to reports breaking tonight, United had £100m available to spend on a world class centre-back this summer, but did not deem any of Mourinho's favoured options as worth spending such big money on.
The Portuguese tactician has supposedly been told there will be no more "quick fixes" in future windows. "We have a very good squad, with very good players and it is very hard to add players to that", he said.
Manchester United begins its season off on the right foot, with World Cup-winner Paul Pogba scoring alongside Romelu Lukaku.
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Despite previously moaning about the quality of his squad, Mourinho has changed his tune. "I like my players and my group".
"I want to challenge and fight until the end, or until that moment when my chairman Daniel Levy says to me 'Mauricio, go home or find another project'".
But Pochettino insisted he is happy with his squad. One lie repeated 1,000 times is still a lie but the perception of people is that it's true.
"When you repeat 1000 times that my relationship with my players is not good, it's a lie, repeated 1000 times it is still a lie".
"I congratulated him and he said 'no gaffer I am really disappointed, I should have scored more goals.' I said 'but you won the Golden Boot.' He said 'yes, but gaffer I'm disappointed'. It depends on the music, but words don't come easy [at this stage]".
It is so like Kane to have tunnel vision on his next goal once one target has been achieved and even though he only returned to Spurs training this week, he'll be eager to play a part on Saturday in their opener at Newcastle United.