United failed to sign any of Mourinho's centre-back targets, and there were some withering comments in the aftermath of the 2-1 win.
"I had my plans for many months and I find myself with the market closed in a situation I did not think I would be in", he said.
'For us, it will be a hard season because I had my plans for many months.
"It is hard for me to understand, we finish second which I keep saying, that I won eight championships and three Premier Leagues but I keep feeling the second last season was one of my biggest achievements in the game".
Brazil worldwide Fred, highly-rated but raw full-back Diogo Dalot and third-choice goalkeeper Lee Grant all arrived at United by early July, but nobody followed despite Mourinho's explicit desire to bring in two more players.
"We must get used to teams who have players of the same quality that we have".
The Red Devils boss has struck a frustrated figure during pre-season ahead of their Premier League opener against Leicester City on Friday night. Every team is a good team, forget the name, forget the history, forget the shirt.
The midfielder featured in two of United's friendlies but Mourinho insists that he didn't have a pre-season and must therefore start in the same position as the players who have just returned from extended holidays after the World Cup.
Pogba overruled Alexis Sanchez when United were awarded an early penalty despite the protestations of his teammate. Bayern Munich defender Jerome Boateng is Mourinho's first choice, but has reportedly phoned the Portuguese coach to tell him he won't be joining. 'The thinking is he is a very good penalty taker and likes the responsibility of it.
Pogba scored for France in July's World Cup final and will hope to transfer his global success to United. Maybe in the next game I can give to Alexis.
'I'm quite young and I want to get better, progress and win more trophies, ' said Pogba.
Manchester United haven't won the Premier League title since 2013.