McCown was with the Saints last season as a backup to Drew Brees.
McCown has 10 years of experience, mostly as a backup, in the NFL and spent time two seasons ago with the Atlanta Falcons.
McCown, 32, has completed 58 percent of his career throws for 2,035 yards, nine touchdowns and 14 interceptions for a 68.3 passer rating.
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Aaron Wilson covers the Ravens for The Baltimor Sun