Derby County have confirmed Jody Morris and Chris Jones are following Frank Lampard to Chelsea.
Lampard was unveiled as the new Chelsea manager on Thursday morning after signing a three-year contract at his former club.
And he has joined by the backroom staff that helped him take Derby to the Championship play-off final last year.
Derby chairman, Mel Morris, said: "Frank, along with Jody and Chris, leave with our best wishes and I sincerely hope they have success at Chelsea.
"I thoroughly enjoyed working with Frank and while we would have loved his time at Derby County to continue, to build on the positives we saw last season, the opportunity for him to return to Chelsea as their head coach was huge.
"As a club, we have enjoyed an excellent working relationship with Chelsea recently and would like that to continue moving forward."
