Calderwood left Kilmarnock at the end of the season, saying he was unhappy about the playing budget and the prospect of losing coach SandyClark to cut costs at the debt-struck club.
Calderwood, who arrived in January with assistant Jimmy Nicholl and coach SandyClark after Jim Jefferies' exit to Hearts, got off to a great start in his capacity as interim manager, enjoying an eight-game unbeaten streak.