That is according to former Premier League star Phil Babb.
The Blues stormed to the title last season as United and City were still in a transition period under new management.
Jose Mourinho and Pep Guardiola still made progress in their first campaigns in charge.
And fans of both United and City are beginning to reap the rewards of the two experienced bosses.
United and City sit joint top on 19 points, having each conceded just two league goals so far.
Chelsea are six points behind the Manchester clubs, although Babb believes they still have talent to compete.
“I can’t see that Chelsea have got weaker,” Babb said on Sky Sports.
“They’ve got (Eden) Hazard back and Hazard looks like he’s playing exceptionally well.
“They’ve got quality players, (Alvaro) Morata’s scoring goals.
“So putting the ball in the back of the net is not going to be a problem.
“But I just think squad-wise, the Manchester clubs are significantly stronger.
“Chelsea are going to be up there (for the title), Spurs as we just mentioned are going to be up there.
“But the Manchester clubs look to be the strongest in the Premier League at the moment.”
On Saturday, City host Stoke, Chelsea travel to bottom of the table Crystal Palace, while United face a tough test at Liverpool.
