Watt diagnosed with fractured tibia in left leg, reportedly out for season

J.J. Watt's season has reportedly met the most unceremonious of endings.

The Houston Texans defensive end has been diagnosed with a tibial plateau fracture in his left leg, an injury he suffered on the first defensive series of Sunday's game against the Kansas City Chiefs.

John McClain of the Houston Chronicle reports the injury will require season-ending surgery.

Watt went down after losing his footing on an early play, and was soon carted off to the locker room with what was initially believed to be a knee injury. He later left NRG Stadium in an ambulance, crutches in tow.

The 28-year-old sees this year's campaign end in Week 5 after back issues limited him to just three games last season. The five-time Pro Bowler came into Sunday's tilt with 13 tackles and a pair of pass breakups on the year.

The Texans' defense took another hit moments prior to Watt's stroke of misfortune, as rush end Whitney Mercilus went down with a chest injury. He's since been ruled out for the remainder of the game.