Head coach Kyle Shanahan said Purdy (shoulder) did some light throwing Monday and didn't have any issues, Nick Wagoner of ESPN.com reports.
Purdy will rest Tuesday and see how the shoulder feels over the course of the week. He was unable to play in Sunday's 38-10 loss to the Packers, and Brandon Allen started and struggled mightily in Purdy's absence, completing 17 of 29 passes for 199 yards (6.9 yards per attempt) and one touchdown with one interception. The 5-6 49ers will have a tough road matchup with the Bills on tap Sunday.