That’s according to his former team-mate Shaka Hislop.
Lampard looks set to take over from Maurizio Sarri as Chelsea manager within the coming days.
Derby County confirmed on Tuesday that they had given the Blues permission to talk to the head coach.
The 40-year-old guided the Rams to the Championship play-off final last season, where they were defeated 2-1 by Aston Villa.
Chelsea currently have the looming uncertainty of the transfer ban hanging over them, and could be unable to strengthen their squad until next summer.
They finished third in the Premier League after a strong end to the season, but Italian coach Sarri chose to move back home closer to family by taking the Juventus job, opening the door for Lampard.
The former Chelsea midfielder spent 13 years at the club, making 648 appearances before leaving for New York City in 2014.
Lampard has spent just one full season in management, and Hislop has doubts about whether or not he will succeed at Chelsea.
Owner Roman Abramovich has a long history of sacking managers, having seen 11 different coaches come and go since 2003.
And Hislop – Lampard’s team-mate at West Ham – explained on ESPN FC that he believes the club should have gone for someone with more experience.
“It ticks all the emotional boxes for Chelsea Football Club,” Hislop said.
“And let’s not forget that Frank did a very good job at Derby County.
“But what was asked from him at Derby and what will be expected from him at Chelsea are two very different things.
“I just fear that a job with the status of Chelsea Football Club, you need a little bit more experience and a little bit more knowhow.
“I’m not sure that Frank has that.
“Also, this job comes with a lot of hurdles that it might not have come with previously, and that’s why the job needs someone with a big more experience.
“I just don’t think, as good a manager as Frank may be, I just don’t think he’s ready right now.”