After going 26-22 in two seasons, new GM Ryan Grigson has decided to let Jim Caldwell go after leading the Peyton-less Colts to a 2-14 season. Owner Jim Irsay has been busy remaking the Colts. Since the end of the season, he has parted ways with the Polians' whom are friends with Manning and Caldwell who was Manning's QB coach for his 4 MVP years.
Irsay and Grigson understand that the talent pool for coaches is rich, but timing will be critical. The Rams were able to sign Jeff Fisher away from the Dolphins after Miami decided to keep Jeff Ireland as GM. Fisher wanted full control.
Tony Dungy in all likelihood would not be an option since he is friends with Bill Polian, Jim Caldwell, and Peyton Manning. Hard to see him replacing friends.
The firing of Caldwell makes the vacancy the most attractive coaching option available. The new coach will have his choice of Peyton Manning and a #1 pick in the upcoming draft. Its a win-win situation. Irsay understands that, so expect a quick decision.