49ers left tackle Joe Staley left Sunday's game after suffering a concussion on the first play of the game. Staley didn't leave the game immediately but was replaced by Alex Boone during the team's next series. The 49ers recently signed Boone to a four-year contract extension, and they feel he can come in and play well at either left or right tackle. Boone played well against the Cardinals Sunday. Source: Sporting News
