Only five men - Alex Ferguson, Arsene Wenger, David Moyes, Rafael Benitez and Gerard Houllier - have previously overseen 100 wins with a single Premier League team.
Mourinho will achieve the feat from just 142 matches should his side claim three points on Sunday.
Chelsea head into the game two points behind leaders Arsenal in third and unbeaten in six league games.
United have also displayed fine league form in recent weeks, winning five out of their last six, but began 2014 with three defeats in all competitions before recording victory over Swansea City last time out.
The defending champions have recorded only one victory in seven games against top-six opposition this season and have failed to triumph in their five most recent meetings with Chelsea.
Mourinho has only overseen three defeats to United in his career, but expects a tough test from Moyes' men, who currently sit seventh in the table.
"My 100th victory in the Premier League with Chelsea is going to happen; is it against United, West Ham or later? I don't know - what I know is that the number will arrive," said Mourinho.
"If I can do it in the next match it's better than doing it in three, four or five matches away.
"We are going to try to do it against Man United because now we play two matches at home, after playing two matches away, and we have to try to go for the six points.
"(But) United are United - 11 points to the leader is quite a lot but I believe they will push all the way.
"The way this league is at the moment, I think for all the big teams the first objective is to secure a place in the top four because it will be difficult to get it."
Moyes revealed on Friday that Wayne Rooney (groin) and Robin van Persie (thigh) will both miss Sunday's game, meaning Danny Welbeck, who has scored six goals in as many league games, will once again take on additional responsibility.
Marouane Fellaini (wrist), Nani (hamstring) and Ashley Young (shoulder) are also sidelined for United and Fabio is suspended.
Mourinho will have new signing Nemanja Matic available after his move back to Chelsea from Benfica, while Frank Lampard has trained all week and is set for a recall.
Branislav Ivanovic and long-term absentee Marco van Ginkel (both knee) are out.
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