Erik Magnuson was one of the big surprises of the 49ers 2017 training camp, coming in as an unheralded UDFA tackle from Michigan, and sticking with the team as the backup center. He played in four games, including one at right tackle due to injuries, and did fine. Not great, but not Beadles-bad either.
He injured his foot against the Seahawks in game 12 last year, when the team was most short-handed due to injuries, and made the questionable decision to keep playing on his taped up foot despite hearing it pop.