Lukaku isn't the only player being reunited Mourinho, who also convinced former club Chelsea to sell Nemanja Matic to United. Since then the manager has plugged the gaps in his team with big new signings.
Romelu Lukaku is a very good striker, and the Belgium global will be determined to make a strong start to the new Premier League campaign for his new club.
"Midfield players scoring goals, wingers scoring goals, central defenders good in the air scoring goals at set-pieces".
"But we have players and if we cannot strengthen the team in these areas we have people we can trust and go for it".
The affliction between the striker and the Red Devils is clear for all to see, Ibrahimovic became a cult hero last season amongst United fans because of his desire to win, his wonderful arrogance and of course his goals.
An argument can be made that, despite spending more than $156 million on players during the summer transfer window, the team isn't better than last year's version.
Romelu Lukaku, Victor Lindelof and Nemanja Matic have so far arrived this summer, but Mourinho always meant to make four acquisitions.
"It's not because I always did it that I am going to do it", the ex-Porto, Chelsea, Inter Milan and Real Madrid boss said.
Jose Mourinho's outfit now looks ready to step up a level from last season and challenge for the Premier League title.
"I just think he was very clear showing what he did a year ago was not enough for him. I have better conditions to deliver a better season than my first one".
"In my initial analysis, coming from January and progressing through the months, I was thinking about four players", Mourinho said.
Despite ending last season on a high thanks to their FA Cup triumph against Chelsea, divisions still run deep at Arsenal over Arsene Wenger's lack of success in the Premier League and Europe over the last 13 years. This time we are all in the same basket, it is going to be the same for everybody. Okay, some will have the luck to play on Tuesday or Wednesday, or Saturday or Sunday.
"The league is special because it is such a tough division to win", Carrick - the last remaining member of 2008 continental champions - said. But we are involved in four competitions.
That is a big change from a year ago, when United played only five pre-season matches after a friendly against Manchester City in Beijing was called off.
"Victor can play right-back and can play central midfielder, we got a central midfielder, we got a striker".
The real signs of how serious United will be this season will come on Sunday afternoon when West Ham is the visitor to Old Trafford.