Tyron Smith inactive for Cowboys' must-win game vs. Redskins

Dallas Cowboys offensive tackle Tyron Smith is inactive for a must-win clash against the Washington Redskins in Week 17 due to a back injury.

Smith missed three days of practice this week. The 29-year-old was also sidelined for two games in early October due to an ankle ailment.

Since being drafted ninth overall in 2011, Smith has emerged as one of the NFL's premier blockers. He is a two-time All-Pro and has been selected to seven straight Pro Bowls.

The USC product is a major piece of the Cowboys' offensive line, which has allowed a league-best 20 sacks through 15 games this year.

Dallas must defeat the Redskins and will need the Philadelphia Eagles to lose to the New York Giants in order to qualify for the postseason.