Schaub is the most experienced and expensive backup that the Ravens have had on the roster since former St. Louis Rams Pro Bowl quarterback Marc Bulger backed up Flacco under a one-year, $3.8 million contract. Bulger wound up not throwing any passes for the Ravens during the regular season that year before retiring.
The Ravens have 2014 sixth-round NFL draft pick Keith Wenning in place as the third quarterback. Schaub replaces former backup Tyrod Taylor, who signed a three-year, $3.35 million contract with the Buffalo Bills this offseason.
Schaub has a background with the Ravens' playbook that was installed last year by former offensive coordinator Gary Kubiak, his former coach with the Houston Texans who left after one season to become the Denver Broncos' head coach. Although the Ravens hired former Chicago Bears coach Marc Trestman as their new offensive coordinator, he's expected to maintain a lot of the schemes that Kubiak put in place last year.
Schaub played for the Oakland Raiders last season after being acquired via a trade with the Texans in exchange for a sixth-round draft pick, but was benched.
Schaub was replaced as the starter by rookie first-round draft pick Derek Carr before being cut after the season. Schaub has dealt with elbow issues recently, but is regarded as healthy now.
Schaub struggled in recent seasons, including last year with the Raiders.
In 11 games -- none of which he started -- Schaub completed five of 10 passes for 57 yards, no touchdowns and two interceptions.
A former third-round draft pick of the Falcons from Virginia, Schaub made the Pro Bowl in 2009 with the Texans when he passed for 4,770 yards, 29 touchdowns and 15 interceptions. Falcons offensive coordinator Kyle Shanahan was Schaub's offensive coordinator and quarterbacks coach in Houston.
For his career, Schaub has passed for 24,311 yards, 130 touchdowns and 86 interceptions with an 89.5 quarterback rating.
During his final season with the Texans in 2013, Schaub passed for 2,310 yards, 10 touchdowns and 14 interceptions. He started eight games before being benched.
During that season, Schaub threw interceptions returned for touchdowns in four consecutive games. That included Ravens middle linebacker Daryl Smith returning an interception for a touchdown in a Sept. 23, 2013 win at M&T Bank Stadium.
In 2012, Schaub passed for 4,008 yards, 22 touchdowns and 12 interceptions.