Manchester United conceded after just 30 seconds to Pedro Rodríguez and succumbed 4-0 at Stamford Bridge, potentially losing their centre-half Eric Bailly to a serious knee injury en route, with Mourinho berating his team's "incredible mistakes" at the back.
Ibrahimovic went close for United in the 81st minute calmly bringing down Valencia's cross but was denied by Courtois who cleared away for a corner.
The United boss spoke at length to Conte at the final whistle, with suggestions the Portuguese had been annoyed that his Italian successor had encouraged the home support to cheer on the Blues when they were already 4-0 up.
And speaking in an interview with Sky Sports before Manchester United's clash with Chelsea on Sunday, Mourinho revealed why he is not hoping to return to Stamford Bridge as manager any time soon.
He told Sky Sports Now: "I don't go with people being exhausted - I just don't think they've got a settled side".
Chelsea are starting to look more like the force they had been before a rift between Mourinho and senior players saw the London club suffer a dramatic dip in form last term.
Pedro added: "For me it's flawless that (manager Antonio) Conte is confident with me".
"I have a three-year contract here (Manchester United) and if I am here for three years the people will know that I have given everything to the club. At 1-0 ok but not 4-0 - that's humiliating to us". "When the players deserve it after this performance, it's right to receive a great clap from the fans".
Conte had urged home fans to make more noise after Kante made it 4-0 in the 70th minute.
Both managers have collected only two points out of a possible nine from their past three Premier League games, and one of their trophy quests will end on Wednesday when City and United meet in the League Cup.
"When you are a Manchester United fan for 30 years, for 50 years, you are going to have hard times like these and you have to accept when they come along and be mature about it".
"Chelsea had a much better start than us and we paid dearly for it".
"It is very important after the Arsenal and Liverpool defeats".
"You can win 10 times and then you are not able to win five times".