Financial terms were not disclosed.
Bradshaw, 27, missed the last half of the 2013 season after having season-ending neck surgery. He was injured on Sept. 22 and was originally supposed to sit out a couple of weeks to see if rest and rehabilitation would heal the injury.
He originally came to the Colts last offseason on a one-year deal worth $2 million. He rushed for 186 yards and two touchdowns in 2013.