Chelsea have lost Jon Harley as part of their Academy setup immediately.
The graduate of the Chelsea youth system, Harley has now joined Portsmouth as an assistant first team coach.
Harley has worked in a coaching role in the Blues' Academy for the past ten years.
The club thanked their former left-back, who played 42 times for the club between 1998 and 2001, for his service.
Harley is now hoping to take the next step in his coaching career.
He will form part of John Mousinho's backroom team at Pompey.