Manchester United were strongly linked with a host of players in the summer months as Mourinho looked to build a squad capable of winning the title this season.
The Red Devils completed deals to bring in Fred, Diogo Dalot and Lee Grant earlier in the window, but they were strongly linked with a move for a new defender before the close of the transfer window last week.
Toby Alderweireld was one of the main names to have been touted as a target for the Red Devils this summer, but the defender ended up staying at Tottenham Hotspur.
Mourinho has now admitted that he was disappointed that the Red Devils were not able to get any more deals across the line before the deadline last Thursday.
Asked if the new season will be more difficult without the signings he wanted, Mourinho told Sky Sports: “Of course it will be. ‘I think it will be a difficult season for everybody, not just for us.
“For us it will be a difficult season because I had my plans, and I had my plans for many months.
“But I find myself in the beginning of the Premier League, with the market closed, I find myself in a situation that I thought I was not going to be in, but I think it’s the last time I speak about it.
“Maybe last time in the press conference if any of your colleagues ask about it. But over, finished, the market is closed. And no more talk about it.”
Manchester United will be aiming to challenge for the Premier League title next season after they finished in second place in the table and without a trophy last term.
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