The Texans lost two of their best players on Sunday night in the setback against the Chiefs.  J.J. Watt and Whitney Mercilus suffered season-ending injuries early in the game.

The impact on the defense will be massive. Both are key components on a unit that has not played well this season, even with them in the lineup.

The Watt injury is particularly devastating. The heart and soul of the defense, Watt missed 13 games last year due to a back injury, and was visibly shaken on the sidelines Sunday night. Watt's incredible fundraising and off-field exploits have made him a local hero, and his loss will be felt throughout the organization and fan base.

From a football perspective, while Watt had yet to record a sack, he was having a massive impact in getting pressure on the quarterback and sometimes tying up 2-3 blockers, freeing up others to make plays. That simply can't be replaced.

Mercilus injury means more time for promising players like Dylan Cole and Brennan Scarlett, who have shown flashes. 

The bigger issue is the play of the defense in general. Mike Vrabel, in his first year as defensive coordinator, has struggled with play calls in key situations. The team has struggled to get pressure on the quarterback, and has given up big plays in the secondary. If that continues, it will waste what is clearly becoming an explosive offense under Deshaun Watson. 

Expect to see a lot more of Cole and Scarlett as well as rookie linebacker Zach Cunningham. The Texans at least have solid depth at LB, which should mitigate the loss of Mercilus somewhat. 

They do not have a valid option to replace Watt. Christian Covington and Joel Heath represent a significant drop-off. Vrabel will have to find ways to adjust his scheme to fit their talents. 

The Texans did OK without Watt last year, but this time it might be too much. There is not much on the free agent market to help, so whatever the Texans do, it will have to be internal.

Watt's loss goes beyond his impact on the field. He is a fan favorite, a leader, and has been the face of the franchise. 

This morning he sent out a heartbreaking tweet.

"I can't sugarcoat it, I am devastated. All I want to do is be out there on that field for my teammates and this city. I'm sorry."

Texans fans and players are sorry, too. The Texans have some big shoes to fill moving forward, and it will not be easy.