The Portuguese manager, making his Sky Sports punditry debut, was questioned about who he believed could lift the coveted trophy in May.
United get their Premier League campaign underway against the Blues on Sunday, but the Portuguese don’t hold much hope for either side ahead of the new season.
He said: ‘Four [teams can win the title]. Man City, Tottenham, Liverpool and Man City B team. The players that were not already involved, I think the [City] B team could fight for the title.
‘I think if one of the teams plays magnificent today, I don’t believe they are going to resist in the title race. I don’t see also Arsenal to resist to a title race. Last season was phenomenal but I think Tottenham has to join it.’
Former United full back Gary Neville agreed with the 56-year-old tactician, and also wrote off the side he supports from mounting a title bid.
He added: ‘I don’t see United winning the title. As a United fan all I want them to do is to create a strategy and stick to it. David Moyes came in, Mata 5ft 8ins, Fellaini 6ft 4ins, then they sacked David Moyes, then Louis van Gaal came in a lot of technical possession players to fit his model. Then they sacked him.
“Today, even if one team plays magnificently or has a fantastic result, I don’t believe the title is possible.”
Both clubs are coming into the 2019-20 season as relatively unknown quantities, with new managers still getting their feet under the table.
Ole Gunnar Solskjaer will be hoping the big-money signings of Harry Maguire and Aaron Wan-Bissaka can help to prove that his promising start to life at Old Trafford was no flash in the pan.
Chelsea, meanwhile, are embracing a new dawn with Frank Lampard at the helm. Restricted by a transfer ban, they are expected to rely heavily on their vast array of youngsters in the coming year.
But whatever they do achieve this season, it seems that Manchester City’s Premier League crown is an unassailable one – for Mourinho’s old clubs, at least.
“Manchester United can’t win the title and I don’t think Chelsea can either,” Neville said.
“I think United would snap your hands off now if you offered them fourth. I think they are in a battle with Chelsea and Arsenal for that position.
“I think Tottenham, Liverpool and City are well ahead.
“Manchester United have got to start one block at a time. You can’t expect them to go from where they have been over the last seven years to winning the title.”
Souness is also ready for another two-horse race, though he thinks Tottenham could piece together another impressive season.