Davis has caught 50 career passes for 561 yards and 12 touchdowns.
He won a Super Bowl last season with the Seahawks.
Davis is a former Bears fifth-round pick from Michigan State.
Harvey was signed as a rookie free agent by the Tennessee Titans last year. He was released in training camp. In two seasons at Florida A&M, Harvey played in 12 games with 10 starts and had 66 receptions for 818 yards and seven touchdowns
As a senior, Harvey caught 64 passes for 808 yards and seven touchdowns.
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Aaron Wilson covers the Ravens for The Baltimore Sun