Mason (ankle) was officially placed on injured reserve Saturday, Adam Schefter of ESPN reports.

Mason (ankle) has been ruled out for Sunday's game against the Bears.

Mason (ankle) did not practice Wednesday, Matt Barrows of The Athletic reports.

The 49ers placed Mason (ankle) on injured reserve Monday, Nick Wagoner of ESPN.com reports.

Mason rushed three times for eight yards with one reception (two targets) for five yards in Sunday's 38-10 loss to Green Bay.

Mason took two carries for 13 yards and was not targeted as a receiver in Sunday's 20-17 loss to the Seahawks.

Mason (shoulder) had one carry for five yards in Sunday's 23-20 win over the Buccaneers.

Mason (shoulder) doesn't have an injury designation for Sunday's game in Tampa Bay, Brianna Dix of the Buccaneers' official site reports.

Mason (shoulder) was a limited practice participant Thursday, Nick Wagoner of ESPN.com reports.

Coach Kyle Shanahan said Monday that Mason aggravated his existing shoulder injury in Sunday night's win over the Cowboys and is viewed as day-to-day, Nick Wagoner of ESPN.com reports.