WHITE SULPHUR SPRINGS, W. Va. — The reality of life playing football is that major knee injuries are common.

What isn’t: Tearing your ACL and then playing three-plus quarters of football after. That’s what happened to Broncos inside linebacker and captain Alex Singleton on Sunday against Tampa Bay, dealing a significant blow to a stout Denver defense just three weeks into the season. Head coach Sean Payton and Singleton’s teammates reacted with equal parts disappointment and amazement at the season-ending injury, its impact and Singleton’s ability to play 49 snaps after sustaining what appeared to be a non-contact injury during safety Brandon Jones’ first-quarter interception return.

“If there’s a story or something that could — if I had to explain Alex in one thing, I would just point that out,” rookie quarterback Bo Nix told reporters at The Greenbrier here after Denver’s Wednesday practice. “Alex is the type of guy who would tear his ACL on the (eighth) play of the game and go out there and finish the game.” Singleton dropped back into coverage on a third down and hopped in apparent pain in the open field.

He ran down to try to block somebody on the return and limped off the field after the play. He told some teammates, including Nix, about his knee being sore at halftime, but he played all 57 defensive snaps. After the game, he reported knee soreness to the Broncos training staff and they did the ACL structure test.

Vice president of player healt.