"I said that during preseason and it looked like I was saying something absolutely out of order, something insane, I repeat: Preseason is hard when you don't have your players to work, that's as simple as that". After missing out on the likes of Diego Godin, Harry Maguire and Toby Alderweireld in the last days of the window, Mourinho will now have to concentrate on the task at hand, as he noted in the pre-match press conference.
Man United chiefs reportedly vetoed Mourinho's targets as they believed he was "targeting defenders who were no better than those they already had".
So how would Man United line up if Mourinho had landed the players he desired?
The Ivorian worldwide was signed by Mourinho for £30m in 2016 and fans consider him to be the best centre-back at the club.
The Ecuadorian wing-back, who recently turned 33, has been one of the most reliable players during Mourinho's two-year reign in Manchester.
However, speaking to BBC Sport's Simon Stone ahead of last season's runners-up's opening outing at Old Trafford, the Portuguese manager damned reports of unrest within his squad and claimed he is ready for the upcoming fight.
Pogba was linked with a move to Barcelona earlier this week but the United board never had any intention of selling him.
This market is now priced at 13/10 (2.30), and that is a price that will already attract significant interest considering United kept 19 clean sheets in the league last term - the most of any team. That "what he's got" includes Phil Jones, Marcos Rojo, Luke Shaw and Matteo Darmian.
After a brilliant World Cup, Perisic is now worth nearly double that figure. Signing Alexis Sanchez when he became available was another.
For all of their attacking and goalkeeping talents, however, most football fans can agree that United's defence needed reinforcing this summer.
Chelsea shattered the world-record fee for a goalkeeper with an 80-million euro (US$92 million) swoop for Athletic Bilbao's Kepa Arrizabalaga on Wednesday to replace Belgian global Thibaut Courtois, who has joined European champion Real Madrid.