The Portuguese was summoned at the end of September over allegations he defrauded the Spanish tax authorities of €3.3 million between 2011 and 2012 during his time in charge of Real Madrid.
At the time the charges were announced in June, Mourinho's representatives issued a statement that denied he had been contacted by prosecutors while insisting he had paid his taxes in full.
The Red Devils usually hold their pre-match news conference on a Friday and, while the club brought forward their media duties by a day to accommodate Mourinho's court date, the manager is adamant it has been business as usual.
"No," he said when asked if it's been a distraction.
"It's just a change of normal training time because I want to be there and I can't be there in the morning, so I have to change the timings."
United travel to Stamford Bridge in second, four points and two places above Antonio Conte's side.
Last season, Mourinho — who won three titles over two spells with the Blues — was booed by sections of the Chelsea crowd, while he has also been involved in verbal sparring with Conte this term.
However, Mourinho played down the significance of his return.
"It's not a big thing to return to Chelsea, it's normal, it's football, it's professionalism," he added.
"It's football life, one day you are in one club and then you are in another club, it's a big thing because it's a big opponent.
"A match between two top teams, but from the emotional point of view it's just one more.
"I played there with Inter and twice with Manchester United. I have to admit it is a little bit different, but in the end I want to win like I did with Inter.
"They want to win like they did last season and it's just one more day.
"In a couple of years we will be even more natural and in even four or five years people will not remember I was Chelsea manager and it will become normal.
"But it's a big match because they are champions and we are Manchester United."