Karney agreed to a three-year, $3.6 million contract that includes $1.2 million in guarantees, according to a source. The Rams have been struggling at that position since they released Madison Hedgecock in 2007. Hedgecock ended up becoming a Pro Bowl alternate for the New York Giants last season.
The signing of Karney gives St. Louis a chance to be more successful in two-back formations. The 27-year-old Karney was named to the All-Pro team in 2006 when he played for the New Orleans Saints. The Saints released him on March 5, putting one of the league's more respected fullbacks on the market. The Rams were quick to have him in for a visit.
The 5-foot-11, 258-pound Karney had 46 career starts in five seasons with the Saints. Karney will be the blocking back for Rams halfback Steven Jackson.
John Clayton is a senior writer for ESPN.com.