Arsenal boss Arsene Wenger does not dispute the quality in Manchester City's ranks but insists Pep Guardiola's men are not unstoppable.
City have been the dominant force in the Premier League this season, and their tally of 31 points and a +31 goal difference is the best return from 11 matches in the competition's history.
Last time out, City were 3-1 victors over the Gunners at the Etihad Stadium in a match that left Wenger seething with the quality of refereeing in the top flight.
The Frenchman felt Raheem Sterling had dived to win a penalty from which Sergio Aguero made it 2-0, while insisting David Silva was offside before setting up Gabriel Jesus to wrap up the match after Alexandre Lacazette had halved the deficit.
Wenger is still frustrated by the decisions made in that game, but is convinced City are not unbeatable.
"They are a good side, but they're not an unstoppable side," he told beIN SPORTS.
"If you look at the expected goals it was 0.7 for them and 0.6 for us. It was a very tight game, they created very little number of shots on target, one more than us, that's all.
"Overall I think we were hugely punished with the third goal. At 2-1 we were hugely in the game.
"I don't dispute they're good, but they not unstoppable. But the referee had an absolutely atrocious impact on the game."
Wenger is the only manager to have led a team to an unbeaten Premier League campaign, with his 'Invincibles' side achieving the feat en route to winning the title in the 2003-04 season.
But Wenger again was non-committal on City's chances of emulating that Arsenal side.
"People always want to predict what will happen," he added. "I don't know more than you.
"Maybe, maybe not. But at the moment only one team has done it."