INDIANAPOLIS — Curtis Painter and Larry Coyer are out in Indianapolis, and it could be just the start of the changes for the winless Colts.

Coach Jim Caldwell broke up a normally quiet Tuesday by announcing that Coyer had been fired as defensive coordinator and that Dan Orlovsky would replace Painter at quarterback when the Colts play Sunday at New England. Longtime linebackers coach Mike Murphy will replace Coyer.

The moves come in the midst of a shocking 0-11 season, the Colts’ worst start since 1986.

“It’s not an easy day,” Caldwell said. “Anybody that would tell you any differently is cold-hearted and callous.”

The relationship between the two coaches dates to the 1970s when Coyer was an assistant coach at Iowa and Caldwell was a player there. And over the past three seasons, Caldwell has gone out of his way to back Painter even after Painter was serenaded by boos when he failed to save Indy’s perfect season in his NFL debut in 2009. Caldwell yanked Peyton Manning in the third quarter against the New York Jets and Indy lost 29-15, dropping its record to 14-1.

Tuesday’s changes could be just the start for Indianapolis.

All the losing has prompted fans to call for the firing of Caldwell, vice chairman Bill Polian and General Manager Chris Polian, both of whom stood behind Caldwell during Tuesday’s news conference. The decision to fire Coyer, Caldwell’s first hire and close friend, will undoubtedly create more speculation about the fate of Indy’s head coach.

The front office also faces a busy offseason in which it will have to make big decisions about Manning, who still hasn’t healed from neck surgery in September, and at least a half-dozen other key veterans.