49ers RB Christian McCaffrey, LT Trent Williams miss practice

The San Francisco 49ers practiced Tuesday without two key pieces of their offense, running back Christian McCaffrey and left tackle Trent Williams.

They were not mere veterans' rest days. McCaffrey appeared on the injury list with a new back issue, and Williams was listed with the right hamstring injury sustained Sunday night in San Francisco's 42-38 win over the Chicago Bears.

The NFC West title and No. 1 playoff seed in the conference are on the line when the 49ers host the Seattle Seahawks on Saturday...