Mason (shoulder) was a full practice participant Wednesday.
Mason initially sprained his left shoulder Week 6 at Seattle, but he paced the backfield Week 7 against the Chiefs before aggravating the issue Week 8 versus the Cowboys. With a bye week to heal up, he's back to full health, but he's also going to be joined in the backfield by Christian McCaffrey (Achilles), perhaps as soon as Sunday's game in Tampa Bay. If that comes to pass, Mason will take a back seat to McCaffrey at running back for the 49ers.