Former Liverpool player and manager Graeme Souness is worried about their title bid.
The Reds are still the favorites to win the league.
They are level on points with City, but have a game in hand.
However, Souness is concerned the title bid may not end in their favor when the season is over.
"Beating Bournemouth has not confirmed that they're back to their best. That result for City [against Chelsea] has confirmed it. It's saying, 'look, we're bang at it. This is how we're going to finish the season,'" said Souness on Sky Sports.
"And if that is their form going into the end of the season Liverpool are going to have to win every game. That's what they're looking at.
"City today have won 6-0 and you're thinking nearly 50/50 per cent of possession, 'were they that good?' Yeah I think they were.
"In areas that mattered, you know when they came to defend they were defending properly as a unit and individually.
"And up front they were getting goals, albeit from some mistakes by Chelsea, but is that papering over something? I don't want to say it.
"They're going to take some stopping aren't they and Liverpool are going to have to win every single game to win this league."