Jurgen Klopp’s side are seven points behind second-placed United and have only won once since August.
Liverpool have a tough run of fixtures coming up and Brazil, who played at Old Trafford for two years, thinks they’ll struggle to make up the points.
“It's an interesting game,” he said on his talkSPORT show.
“The outcome of the game interests me. If Liverpool lose they have to go to Tottenham next.
"So their title challenge could be well and truly over.
“I think the way Jose feels as well, the way City are playing, that he won't want to drop any points in this fixture.
“He'll be going for three points because City at the moment look absolute class.”
Liverpool will be without star man Sadio Mane who has been ruled out for six weeks with a hamstring injury.
Manchester United have injury concerns of their own as Belgian midfielder Marouane Fellaini suffered knee ligament damage while on international duty.
Jose Mourinho’s side are unbeaten so far this season but Liverpool boss Jurgen Klopp has only lost once to the Portuguese in seven meetings.
