Williams suffered a rib injury during Sunday's game against the Saints, Tori McElhaney of the Falcons' official site reports.
Williams remained on the turf after a run of no gain on the first play of Atlanta's second offensive possession. He eventually made his way off the field with team trainers and went to the locker room. Considering rookie fifth-rounder Tyler Allgeier was a healthy scratch Week 1, Cordarrelle Patterson may be in store for a significant workload if Williams isn't able to return.