HOUSTON, TX - DECEMBER 22: J.J. Watt #99 of the Houston Texans enters the field before the game against the Denver Broncos at Reliant Stadium on December 22, 2013 in Houston, Texas. (Photo by Scott Halleran/Getty Images)

A dark horse from the AFC just suffered a major blow with serious injury to star defender

This could derail the Texans' playoff hopes.

Three-time Defensive Player of the Year and Houston Texans defensive end J.J. Watt will miss at least six weeks as he recovers from back surgery, per NFL Network's Ian Rapoport.

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Watt hasn't missed a game over his five-year career, registering 74.5 sacks and 298 tackles over his career.

The 6'6", 290-pound Watt would be sorely missed on a Texans team looking to compete in a weak AFC South.

The Texans (9-7) won the division last season and were stomped by the Kansas City Chiefs in the Wild Card round, 30-0.

With the additions of offensive weapons quarterback Brock Osweiler, wideout Will Fuller and running back Lamar Miller, Houston is expected to be a dark horse contender in 2016-17.