Speaking at a press conference on Friday, the Portuguese manager stated that his player will have a medical with the Premier League champions ahead of a big-money move, per Chelsea's official Twitter account:
Mata has fallen out of favour since Mourinho's return to the West London outfit, starting in just 11 of a possible 22 Premier League games this season.
However, Mourinho was eager to reinforce the view that he held great respect for the creative midfielder, saying that the offer received from Manchester United was suitable:
Mourinho's most intriguing comment was in regards to the role Mata still could have played for the Blues, despite not actually being on the books at Stamford Bridge:
This quote could well be in reference to Arsene Wenger's view that the timing of Mata's transfer promises to hurt the Premier League title hopes of those outside West London.
I am surprised. Juan Mata is a great player and they sell a great player to a direct opponent. Chelsea have already played twice against Man United, they could have sold him last week.
I think if you want to respect the fairness for everybody, this should not happen.
I can understand completely what Chelsea are doing, and they do not make the rules, but maybe the rules should be a bit more adapted for fairness.
The Gunners are scheduled to host United in three weeks' time, and one would have to assume that Mata will be in the lineup that faces Wenger's side.
However, when asked about such ulterior motives on Friday, Mourinho insisted that Chelsea wish Mata the best in his new surroundings, hinting that the Blues' two-time Player of the Year will be a success further north:
The 25-year-old's £37 million move to Old Trafford is a transfer record for David Moyes' club, eclipsing the £30.75 million fee for which the side bought Dimitar Berbatov in 2008.
With only certain details left to be worked out, it seems only a matter of days, perhaps hours, until Mata is confirmed as Manchester United's latest big investment.