John Eustace has joined Queens Park Rangers as Steve McClaren's assistant manager.
Eustace leaves Kidderminster Harriers, whom Burton Albion are due to play as part of their pre-season preparations this summer.
Albion travel to the National League North side on July 17 , but their plans for another tilt at promotion to the National League will have been scuppered by Eustace's departure.
He joins former boss McClaren at QPR following the ex-Derby head coach's move to West London last week.
"I can't wait to get going with QPR," he told the club's website .
"I have enjoyed two years managing at Kidderminster and that was a great experience for me
"Now I have a great opportunity to develop and I couldn't be learning off anyone better than the gaffer (Steve McClaren).
"I had two great years with him at Derby and learned so much. His coaching is fantastic and the boys here are going to benefit from that 100 per cent.
"I can't wait to help the players here to develop in the way the gaffer helped me."
Eustace was signed by current Burton boss Nigel Clough twice during his time as Derby County manager, on loan from Watford in 2009 and then permanently in 2013.
There will now be no reunion between the pair, but the Harriers are hopeful that a new appointment will be in place by the time Clough's side travel to Aggborough.
"Following John's agreement to join QPR the club have actively identified targets for a new manager and hope to be able to make a positive announcement shortly," a statement read .
