Jimmy Calderwood has cited financial issues for his decision not to manage Kilmarnock in the SPL next season.
Calderwood was appointed in January on a five-month contract but confirmed on Monday he would not be signing an extended deal at Rugby Park.
He had been told that assistant Sandy Clark would not be retained in order to cut costs and Calderwood was unhappy with the budget outlined to him.
"I couldn't fulfil my ambitions under those financial limitations," Calderwood told BBC Scotland. "To be honest, it was more to do with the budget and Sandy leaving.
"To have a fighting chance of making the top half of the table, the budget wasn't enough. It would have made it very difficult to do that and take it on to another level."
Calderwood steered Kilmarnock to safety on the final day of the SPL season.