Heyward-Bey is a former Raiders first-round draft pick from Maryland.
He played last season for the Indianapolis Colts under a one-year contract.
Heyward-Bey caught 64 passes for 975 yards in 2011 for the Raiders.
Last season, Heyward-Bey played in every game and had 11 starts with 29 catches for 309 yards.
For his career, he has 169 catches for 2,380 yards and a dozen touchdowns.
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Aaron Wilson covers the Ravens for The Baltimore Sun