The Indianapolis Colts placed running back Donald Brown on injured reserve with an ankle injury and signed two veterans to help share the load with rookie Vick Ballard.
Delone Carter, who is listed as the current backup to Ballard, is also hobbled with an ankle injury and his availability for Sunday's showdown with AFC South rival Houston is uncertain.
To pad the depth chart, the Colts signed running backs Deji Karim and Mewelde Moore to the active roster and placed Brown and fullback Robert Hughes on injured reserve.
Karim has played in 23 career games. The 5-9, 203-pound back was added from waivers by the Colts on April 30, 2012 before being waived-injured on Sept. 10. Karim was a sixth round pick (180th overall) in 2010 and spent two seasons with the Jaguars.
Moore, a nine-year veteran, played in six games this season with the Colts. He rushed nine times for 14 yards and caught four passes for 36 yards and a touchdown. He was signed by the Colts as an unrestricted free agent on June 19, 2012 before being waived on Oct. 29.