Dan Ashworth will leave West Bromwich Albion this weekend to take up his technical director's post at the FA on Monday.
Ashworth, who will be based at the National Football Centre at St George's Park, is leaving West Brom with mixed emotions.
He said: "I have had nine fantastic years here and I just want to say a big thank you to everyone connected with the football club - the staff, players and supporters.
"As with any football-related job, there have been some lows but we have managed to bounce back from them all and there have undoubtedly been far more highs.
"With the January transfer window now closed, the team having already amassed 40 points and Richard very much hands on in his new role, we all agreed this would be an appropriate time for me to move on.
"But I will continue to help the club in any way possible in my consultancy capacity."
Ashworth added: "It was a really tough decision for me to leave but the FA presented me with a wonderful opportunity which I could not turn down.
"I've worked closely with Richard for the past two and a half years and he has all the attributes to be a fantastic sporting and technical director.
"I have every confidence he will make a real success of the role."