Robbie Fowler cannot see Manchester United denying City in their derby clash in their current form, but the Liverpool great is hopeful.
Liverpool are hoping for a favour from their rivals, with Jurgen Klopp's men two points clear atop the Premier League but with Manchester City holding a game in hand.
United go into Wednesday's derby at Old Trafford on the back of six losses in their past eight games, including a 4-0 thrashing at Everton.
Fowler, appointed coach of A-League club Brisbane Roar on Tuesday, said it was hard to see United turning their form around.
"I think obviously everyone knows my allegiances are massively with Liverpool and I think if we're being totally honest it's going to be tough for them because you feel as though Manchester City can beat anyone on their day," he told a news conference.
"They've got four games to play and obviously they're four winnable games.
"So, to use a little bit of mind management if you like, I think Manchester United need to pull off a big favour for Liverpool.
"I think the way they're playing at the minute, you can't see it happening, but stranger things have happened."
United are chasing a Champions League qualification place, Ole Gunnar Solskjaer's men three points adrift of fourth-placed Chelsea ahead of the derby.