49ers QB Brock Purdy (shoulder) did some "light throwing" on Monday and felt good, HC Kyle Shanahan said. “We didn’t push him that hard,” Shanahan added. “But he did some light throwing, which was a good sign. We’ll rest him tomorrow and see how he feels as the week goes.” Two MRIs on Purdy's throwing shoulder last week -- one on Monday, one on Thursday -- revealed no structural damage. Purdy seemingly has a chance to return for Sunday night's game vs. the Bills, but we'll keep you updated on his progress throughout the week. Shanahan said QB Brandon Allen would get another start in Buffalo if Purdy is out.