The players went on the COVID-19 reserve list Dec. 22.
Johnson joined the team’s practice squad Nov. 11. He has not seen game action since 2018 with Washington.
White, a former first-round choice of the Bears, has spent the season on the 49ers’ practice squad. He has played three games, seeing action on nine offensive snaps and 22 on special teams.
White has returned one kickoff for 20 yards.