Coach Kyle Shanahan indicated after Sunday's 30-24 win over the Cowboys that Mason (shoulder) could have come back into the game if necessary, Matt Maiocco of NBC Sports reports.
Mason was deemed questionable to return after a first-half shoulder injury. He was never officially ruled out but watched Isaac Guerendo handle 14 carries for 85 yards and a touchdown. Mason will have some extra recovery time with the 49ers on bye in Week 9 before traveling to Tampa Bay for Week 10.