Taliaferro, a fourth-round draft pick in 2014, has had each of his three NFL seasons end on injured reserve. He missed the first six games of this season while being on the physically unable to perform list with a foot injury and he lasted only three games before going on IR with a hamstring injury.
Louis, 23, has spent time with the Arizona Cardinals and the New Orleans Saints. He played one game with the Cardinals this year before reaching an injury settlement and he was then released from the Saints' practice squad on Dec. 7.
An undrafted rookie this year out of LSU, Louis is a versatile athlete who can play safety or inside linebacker. What likely interested the Ravens was his experience playing on nearly every unit of special teams.