The Falcons placed Smith-Williams (lower leg) on injured reserve Saturday, Daniel Flick of SI.com reports.
Smith-Williams appears to have aggravated a tibia injury during the Falcons' Week 10 loss to the Saints, per Flick. Smith-Williams will be required to sit for at least the next four regular-season games, and the earliest he can return is Week 16 against the Giants on Sunday, Dec. 22.