Lampard led the Rams to the Championship play-off final last season - his first year in management.
Frank Lampard becoming Chelsea manager "looks like it's going to happen", says his uncle Harry Redknapp.
Derby boss Lampard, 40, is the favourite to replace Maurizio Sarri after the Italian left Stamford Bridge to take charge of Juventus.
Lampard led the Rams to the Championship play-off final last season - his first year in management.
"If Chelsea comes calling, it's a difficult one for him to turn down," Redknapp told BBC Radio 5 Live.
"In my personal opinion, he'll be the manager of Chelsea.
"It looks to me like it's going to happen."
Redknapp - who managed teams including Portsmouth, Southampton, West Ham, Tottenham, and QPR - revealed he had personally told Derby chairman Mel Morris to hire Lampard, who he says "wasn't even on the radar".
If Lampard was to return to Stamford Bridge, where he won three Premier League titles and the Champions League as a player, Redknapp says there would be little pressure on him.
"It's a no-lose situation unless he finishes outside the top six. Anything in the top six would be ok, but the Champions League would be a good season," he said.