United, who have just one win in their last 15 meetings with Chelsea at Stamford Bridge, are also looking to close the gap on table-topping neighbours Manchester City.
"It is a big match, a match between top teams in country... It is a big match because they are champions. But from an emotional point of view, it is just one game," Mourinho told a news conference on Thursday.
"It is normal... It is football life. One day you are in one club, the next day you are in another... In four or five years no one will remember I was Chelsea manager."
United were hammered 4-0 at Stamford Bridge last season but Mourinho, who guided Inter Milan to two Champions League wins over Chelsea seven years ago, suggested that he wanted his team to win in the manner the Italian side did.
"I played there with Inter, twice with United," added Mourinho, whose treble-winning Inter Milan ground out 2-1 and 1-0 wins. "I have to admit it is a little bit different. In the end, I want to win like I did with Inter."
The Portuguese said United deserved credit for their gritty defensive performances amid recent criticism of their approach to games.
"Similar performances for other clubs are magic, or examples of brilliant tactics and amazing attitudes by the players. For other teams the same kind of performance becomes conservative, negative," he said.
"As an example, Tottenham beat Liverpool 4-1 and Real Madrid 3-1. They didn't score against Manchester United. A bit of credit that my players deserve."
Mourinho said the next two days will decide if any of his injured players would return. United are without midfielders Michael Carrick, Marouane Fellaini and Paul Pogba while Zlatan Ibrahimovic and Marcos Rojo are long-term absentees.
United have 23 points from 10 games, while Chelsea are fourth in the table with 19 points.
(Reporting by Shrivathsa Sridhar in Bengaluru, editing by Pritha Sarkar)
