Robertson told the club's official website: "I'm extremely sad to be leaving St Johnstone but it is the right thing for me to return to living in Ayrshire at this point in time.

"I've thoroughly enjoyed being a part of this great Football Club.

"The chairman and the board have always been extremely supportive and we've enjoyed an excellent working relationship.

"Callum Davidson has also been superb with me. It was a pleasure to work with him and to see the team achieve so much this season was very satisfying.

"To win the Betfred League Cup and finish in the top six made it a memorable campaign and gave me some of my happiest moments in football.

"I leave behind a lot of first class colleagues in every department of the Football Club.

"I wish Scott Boyd the very best of luck in his role and I know, moving forward, the club will be in good hands to achieve continued success in the future."

Chairman Steve Brown said: "Kirsten informed us of her change of circumstances a couple of months ago.

"We are sorry to see her go but respect her reasons. We all wish her every success in the future.

"That said, we are delighted she has agreed to remain involved as a consultant, particularly on match days, to enable a smooth handover to the new head of football operations.

"I'm appreciative of the gesture from Kirsten and it will help us to continue to thrive.

"Kirsten has been dedicated to her job and has been a true asset to the Football Club.

"In particular, her contribution over the summer period at the height of the Covid pandemic was invaluable when many hours were spent in meeting the multitude of challenges that were faced by the club at that time.

"She helped identify candidates to succeed her as head of football operations and we are delighted to have Scott Boyd joining the club.

"Scott will have an excellent support network from within the Football Club."