The Texans placed Smith (foot) on injured reserve Tuesday, Greg Auman of Fox Sports reports.
The offensive tackle is set to miss four to six weeks with a torn plantar fascia tendon. Smith was carted off the field last Wednesday with the injury, making Trent Brown the Texans' starting right tackle for the Week 1 matchup with the Bills. Even if the 30-year-old Smith recovers quicker than his timeline predicts, the tackle will need to miss at least four regular-season games on IR (unless he works out an injury settlement with the team) before becoming eligible to return to the team's active roster.