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.

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.