Regardless, the Ravens started training camp without him, and because of NFL protocol he might miss 10 days. (According to a memo shared with teams, an unvaccinated player who tests positive and is not showing symptoms must self-isolate for 10 days.) Harbaugh tried to downplay Jackson’s absence, but the Ravens spent most of this offseason preparing to draft rookie receivers Rashod Bateman and Tylan Wallace and signing free agent Sammy Watkins to increase production in the downfield passing game.