McCabe was a coach at Hamilton Academical as he helped nurture Hartley through the ranks and he will perform a similar role next season by offering guidance to the Dundee manager.
"I got the call from Paul a week ago asking about my situation at Queen of the South," said McCabe. "We go a long way back to Hamilton. Paul has now brought me here based on my experience in football and he knows the way I work. I am delighted that he asked me to come along."