The Chiefs on Saturday promoted defensive back Neiko Thorpe from the practice squad and released center Bryan Mattison.

The Chiefs’ secondary has been hit hard by injuries this year. Cornerback Brandon Flowers has missed time because of a heel injury and safety Kendrick Lewis has not played this season because of a shoulder injury. He also was absent from practice Thursday because of a personal issue.

Thorpe, 6 feet 2 and 185 pounds, was added Sept. 1 to the practice squad as an undrafted rookie free agent. He made seven interceptions in a 51-game college career at Auburn. Mattison joined the Chiefs on Sept. 26 and was inactive for last week’s game against San Diego.