INDIANAPOLIS — The Indianapolis Colts hired Baltimore Ravens defensive coordinator Chuck Pagano as their new head coach on Wednesday.

The team said Pagano will be introduced at a news conference on Thursday. It will be the first head coaching job for the 51-year-old Pagano, who has been a career assistant until now with stops in Oakland and Cleveland in the NFL and stints at schools including Miami and North Carolina.

He replaces Jim Caldwell, who was fired after the Colts’ 2-14 season in which quarterback Peyton Manning never played a down as he recovered from neck surgery.

The move is just the latest in a dizzying series of changes by owner Jim Irsay.

The Colts fired Caldwell last week after three seasons. The team went to the Super Bowl during Caldwell’s first year, but this year locked up the No. 1 overall draft pick with a horrid performance that also cost team vice chairman Bill Polian and his son, general manager Chris, their jobs.

Irsay has since hired 39-year-old Ryan Grigson as the new GM while letting go of Caldwell’s staff. In all, 11 of the 20 coaches who started the season are gone and others they may go, too, once Pagano arrives.

Pagano spent three years as the Ravens’ secondary coach before replacing Bryan Mattison as Baltimore’s defensive coordinator a year ago. The Ravens ranked third in total defense and allowed the third-fewest points in the NFL.