The former Scottish international defender was due to be unveiled at Northampton’s Sixfields Stadium this evening after accepting the job.
The 38-year-old joined our coaching staff in the summer of 2001 as manager of our Reserves having previously played for us between 1993 and 1999, making 198 appearances and scoring eight goals.
Our Director of Football and Caretaker Manager, David Pleat, said: "Colin leaves us with our very best wishes. He's had two-and-a-half years here as a coach which I’m sure has been valuable experience.
"Colin is young, he has energy, ideas and, most importantly, ambition. This could be a terrific apprenticeship for him and everyone at the Club wishes him well in his new role."
Reserve Team Manager Colin Calderwood has left the Club to take over as First Team Manager at Northampton Town.