Johnson made the Pro Bowl after both the 2005 and 2006 seasons when he rushed for 1,750 and 1,789 yards, respectively.
Johnson's best season since then came in 2008 when he rushed for 874 yards and scored five touchdowns.
His numbers dipped considerably the last two years. He played in only two games with Washington last year, gained 2 yards on five carries, before being released.
Johnson is a 6-foot-1, 235-pound power runner who has rushed for 6,221 yards and 55 touchdowns, catching 154 passes for 1,373 yards and six touchdowns.
A former first-round draft pick from Penn State, he rushed for 2,159 yards and 29 touchdowns as a senior for the Nittany Lions. Johnson's father, Larry Sr., is the defensive line coach at Penn State and he guided 2010 Dolphins first-round pick Jared Odrick.