Hull was a freshman All-American as a punt returner at Rice, but did not get much playing time during the team's three exhibition games.
NFL teams must get their rosters down to 75 players by tomorrow.
More San Francisco 49ers News
Anthony "Spice" Adams to announce 49ers' draft picks in 2nd and 3rd rounds George Kittle's message to Brandon Aiyuk amid contract talks with 49ers: "Be patient" Report: Several teams inquiring about 49ers' Deebo Samuel and Brandon Aiyuk Rapoport: Brandon Aiyuk's status 'firmly up in the air' as 49ers near draft