The Ravens signaled their interest in upgrading the backup quarterback position when they made an unsuccessful run at Brandon Weeden before he signed with the Dallas Cowboys in March.
Coach John Harbaugh reinforced that notion during the NFL owners meetings when he discussed backup quarterback Tyrod Taylor and noted that the former sixth-round draft pick was heading into the final year of his contract.
The Ravens have been exploring college quarterbacks, visiting with Eastern Illinois' Jimmy Garoppolo and Virginia Tech's Logan Thomas, while also keeping an eye on the relatively thin, veteran backup market that includes Brady Quinn, Rex Grossman, Josh Freeman, Jimmy Clausen, Matt Flynn and Rusty Smith. (Grossman was a backup for Ravens offensive coordinator Gary Kubiak in 2009 with the Houston Texans, but a source indicated the Ravens haven't expressed interest yet in him.)
The Ravens could also wait to see if the Texans cut loose T.J. Yates or Case Keenum after the NFL draft, where coach Bill O'Brien has said the team might draft as many as two quarterbacks.
But one other available quarterback who has an extensive background with Kubiak is David Carr, who started one year for Kubiak in Houston in 2006.
Carr, 34, has been working out regularly with his younger brother, Derek Carr, as the Fresno State quarterback prepares for the NFL draft. The younger Carr is a projected first-round draft pick.
David Carr hasn't played in an NFL game since the 2012 season, when he was a backup to Eli Manning with the New York Giants. Carr was cut by the Giants prior to last season.
During his last year as a regular starter in 2006, Carr completed 68.3 precent of his throws for 2,767 yards, 11 touchdowns and 12 interceptions for an 82.1 passer rating.
Carr is familiar with Kubiak's offense, remains in good shape by all accounts and has a lot of experience with 11 NFL seasons.
The top overall pick of the 2002 NFL draft took a beating with the Texans, standing -- and often falling -- behind one of the worst offensive lines in the league. But has no known health issues and is unlikely to be expensive.
For his career, Carr has passed for 14,452 yards, 65 touchdowns and 71 interceptions for a 74.9 passer rating.
The Ravens have yet to make a move on Carr at this time, but he could make a lot of sense for them as a proven option to back up Joe Flacco.