Apparently, seeing the Ravens' defense allow 350 passing yards to the Raiders while playing without two of its top three cornerbacks was enough for Ozzie Newsome to take action.
Johnson, 33, is a nine-year veteran of 73 NFL games who could help shore up the shorthanded secondary. Top cornerback Lardarius Webb is out for the year following knee surgery and former first-round pick Jimmy Smith missed Sunday's win over Oakland with a groin problem. Smith's status for this week's game against the Steelers is uncertain.
Johnson hasn't played since Dec. 4, 2011, a day before the shooting death of his sister - an incident where his mother was also shot. That led to him sitting out the remainder of last season.
A 2003 seventh-round draft pick of the Packers, Johnson was traded to the Rams in 2005 before playing five seasons (2007-11) with the Raiders. His contract was terminated by Oakland in March after he was placed on injured reserve in December. Johnson was not in training camp with anyone this summer.
The 6-foot-1, 200-lb. defensive back started 29 of his 59 games with the Raiders, intercepting eight passes, defending 45 and forcing two fumbles. Johnson's best season came in 2009 when he started all 15 games he played, recording three interceptions and 18 passes defended.
Update: The Ravens have re-signed quarterback Dennis Dixon to the practice squad, and released safety Omar Brown from the practice squad. The move prevents the Steelers from picking up Dixon, who played for Pittsburgh from 2008-2011, as insurance for the injured Ben Roethlisberger. On Nov. 29, 2009, Dixon started for a sidelined Roethlisberger (concussion) in the Steelers' 20-17 loss to the Ravens in Baltimore.