Diarmuid O'Carroll has left St Mirren to take up a position as under-21 lead coach at Newcastle.
The highly-rated coach - who is involved in the Northern Ireland international set-up - has accepted the post at Newcastle after two years in Paisley.
St Mirren will now appoint a new head of transition phase and first team coach. However, O'Carroll's direct replacement has been confirmed as Brian Kerr.
"Diarmuid has been excellent for us," said Robinson. "An opportunity arose and it’s a terrific opportunity for him. We wish him nothing but success and we thank him for the part he has played in our relative success as well.
"We’re a club that develops coaches and moves people as well as players and Diarmuid is another example of this.
"Brian Kerr will be moving up to assistant manager. As any good club with organisation does, you prepare for these things. Brian was already in place and has worked with the first team for the last year as well. He will be a fantastic replacement for Diarmuid.
"We will appoint a new Head of Transition Phase and first team coach. We again thank Diarmuid for his hard work and wish him nothing but success."
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O'Carroll said of his St Mirren departure: "I’ve had two-and-a-half fantastic years and I’ve made memories that I will never forget.
"I’ve no doubt that the club will continue to grow and prosper with the manager at the helm, and I wish everyone associated at the club, from the board to the fans, nothing but continued success."
On stepping up to become assistant manager Kerr commented: "I’m delighted to be given the opportunity.
"I’ve been working with the manager and the first team group for a while now but to move up to assistant is something I’m really looking forward to.
"I’ve been an assistant previously. It’s something I’m excited about and a good result at the weekend puts us in a good position going forward."