Bobby Rainey's rookie campaign came to an abrupt end Tuesday when he was placed on injured reserve by the Ravens because of a knee injury.
The team replaced the running back with cornerback Chris Johnson, a free agent who has played in 73 career games. He was a seventh-round pick of the Green Bay Packers in 2003.
Johnson has 157 career tackles and eight interceptions. He last played for the Oakland Raiders, who terminated his contract in March.