Mallett started four games with the Texans this season before being cut on Oct. 27. He threw three touchdown passes and four interceptions.
Mallett was selected out of Arkansas by New England in the third round of the 2011 draft. He appeared in four games in three years with the Patriots before being traded to the Texans in August 2014 for a draft pick.
Over his career, the 27-year-old Mallett has played in 13 games, throwing five TDs and seven interceptions while compiling a lackluster 62.7 quarterback rating.
In other moves Tuesday, the Ravens placed defensive end Chris Canty on injured reserve with a torn pectoral muscle; waived quarterback Bryn Renner and running back Raheem Mostert; and signed running back Terrence Magee and cornerback Jumal Rolle off the practice squad.
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