The former England midfielder is close to sealing a return to the Blues, after one year as manager of Derby County, who he led to the Championship play-off final before losing to Aston Villa.
Petit and Lampard spent three years together in Chelsea’s midfield between 2001 and 2004, but the Frenchman has warned his former team-mate of the gulf in standards.
He told Paddy Power:
“Frank Lampard has many qualities. He’s a very dedicated person, who loves football and has total respect for his team-mates and managers. He is always ambitious.
“But somewhere in my mind I have a feeling the Chelsea job could have come too soon for him. We saw what he brought to Derby County, leading them to the playoffs, but that wasn’t the end of the story for them and they ended up failing to earn promotion.
“He’ll face increased expectation at Chelsea, and he knows this, having played for the club for so long.”