Mullens will be San Francisco's starting quarterback moving forward, beginning with Thursday's game against the Packers, as Adam Schefter of ESPN reports that Jimmy Garoppolo (ankle) will be sidelined indefinitely to allow his high-ankle sprain to heal. Garoppolo is expected to miss at least six weeks, per Schefter.
Mullens was outstanding in relief of Garoppolo in last week's loss to Seattle, throwing for 238 yards and two touchdowns in just a quarter of action. The 25-year-old quarterback has four touchdowns versus three interceptions in four appearances this season, and Mullens won't have the benefit of throwing to George Kittle, as Ian Rapaport of NFL Network reports that the standout tight end will miss extended time due to a fracture in his foot.