Joe Staley injury: Left tackle out for remainder of 49ers-Rams with knee injury

The San Francisco 49ers have announced that left tackle Joe Staley is out for the remainder of the game. Staley suffered a right knee injury on the 49ers opening drive of the game. He walked off under his own power, but immediately went back to the locker room.

The 49ers moved Joe Looney into the starting lineup at right guard, and moved Alex Boone out to left tackle. Adam Snyder is already in the starting lineup at left guard in place of Mike Iupati. This move leaves the 49ers with Daniel Kilgore as their only reserve lineman.

There is no word on the nature of the knee injury, but the quick departure is certainly not a good thing. The 49ers now have now basically replaced three positions with one starter and two reserves. Boone has spent the last two seasons primarily at right guard, last playing tackle at the end of the 49ers Monday Night Football win over the Bears last season. Looney made his pro debut last week with three snaps late in the game. He will now get a whole bunch of work the rest of the game.