Aberdeen are lining up a move for Oldham midfielder Gary McDonald.
The former Kilmarnock player has enjoyed a successful spell at Boundary Park but is understood to be keen on a move back north.
"I can't say too much about things but I expect to speak to Aberdeen this week," said McDonald.
"But I would rather any future details were discussed with my agent at this stage."
With Barry Nicholson, Josh Walker, Jackie McNamara and Sone Aluko all leaving the club, the capture of the 26-year-old McDonald will be crucial if Calderwood is to bolster a depleted midfield.