Boller, a former first-round pick of the Ravens who engendered a fair amount of fan acrimony during his trying tenure in Baltimore, spent last season as a backup for the Oakland Raiders. Dixon, who the Ravens know well from his time with the Pittsburgh Steelers, previously has visited the Denver Broncos and St. Louis Rams and has flashed well as a spot starter.
The Ravens are very high on young quarterback Tyrod Taylor as Joe Flacco's backup and are likely to expand their set of "Wildcat" type plays for Taylor this season, but Dixon and Boller are both more experienced drop back passers as well, which would be more in line with how Flacco runs the offense if they needed depth in the event of injury to their starter.
Baltimore will also work out former Indianapolis Colts quarterback Curtis Painter, along with Boller and Dixon, a club source told NFL Network's Albert Breer.
Painter started eight games for the Indianapolis Colts last season where he completed 132 passes for six touchdowns and 1,541 yards.
Follow Jason La Canfora on Twitter @JasonLaCanfora.