Anthony Barry is to leave his position as assistant to Republic of Ireland manager Stephen Kenny to take a job with the Belgian national team.
The Chelsea coach was credited as being a key figure in the revival of the Irish team under Kenny towards the end of the World Cup qualification campaign.
35 year old Liverpudlian Barry joined the Irish set up in February 2021, but will now join Roberto Martinez as Belgium bid to win the 2022 FIFA World Cup in Qatar.
Belgium are currently the number one ranked team in world football.
Barry has hailed Stephen Kenny's management in a parting statement released by the FAI.
"I've thoroughly enjoyed my time with the team and really enjoyed working with Stephen and the entire backroom staff and players. I've been fortunate to work with some outstanding managers in my career and Stephen certainly falls into that bracket," he said.
"The opportunity to move on to Belgium and to have the chance to take part in the World Cup Finals was one I felt I couldn't turn down. Of course, I wish all of the team the very best of luck for the future."
Kenny has expressed his gratitude to Barry for his contribution.
"I'd like to thank Anthony for the positive contribution he has made over the past year with the players and staff alike.
"Anthony had a great rapport with the staff and players, he was thought-provoking, an exceptional coach and a joy to work with. We respect his decision and he leaves with our best wishes."
Coincidentally, Belgium are the Republic of Ireland's next opponents in a friendly international at the Aviva Stadium on Saturday March 26th.