San Francisco 49ers head coach Kyle Shanahan and general manager John Lynch share a moment on the field during practice. San Francisco 49ers free agency has brought both progress and uncertainty for the San Francisco 49ers as they reload for another Super Bowl run. Under general manager John Lynch and head coach Kyle Shanahan, the Niners have again tried to balance short-term star power with long-term roster sustainability — a tricky equation when so many key veterans are p