Garoppolo will sit out of Thursday's preseason finale against the Chargers, Tom Pelissero of NFL.com reports.
Garoppolo brought an instant spark to the aching 49ers last season and is a lock to be their Week 1 starter, so there's no use in pushing him further. He played in three exhibition contests, completing 22 of 37 passes for 307 yards, one touchdown and one interception. C.J. Beathard will start in his place.