The 'must-win' designation is hardly ever hauled out this early in the season, but for the 49ers to entertain any legitimate thoughts about winning the NFC West when the regular season ends, beating the Rams at home is imperative.
At 4-4 St. Louis is a surprise leader of the division, yet with the Rams at just .500, the Niners are in striking distance heading into the game.
Troy Smith will start at quarterback for the Niners in place of Alex Smith who is inactive. The 49ers are coming off a bye week having won their last game in London against Denver 24-16 with Troy Smith at the helm.
Join the conversation with this NBC Bay Area Sports live blog as the 49ers season hangs in the balance.