The 49ers have made a veteran addition to their offensive line.
Johnson spent the 2018 season with the Dolphins and appeared in 10 games. He spent the previous three seasons with the Jets and took over as their starting center after injuries brought Nick Mangold’s career to an end during the 2016 season.
Lucas signed to the team’s practice squad last December. He has bounced around the league since 2014 without appearing in a regular season game.