No one's questioning Justin Herbert's toughness after the ending of Thursday night's Los Angeles Chargers game, but there may be some concern over his availability in the near future.

The Pro Bowl quarterback went down hard in the fourth quarter against the Kansas City Chiefs on a hit from defensive end Mike Danna and stayed down for a few minutes in apparent pain. Before the game went to commercial break, he could be seen clutching his left side.

As rough as Herbert looked before the break, he only ended up missing one play. Stalwart back-up quarterback Chase Daniel relieved Herbert for one play, a hand-off to running back Sony Michel, before Herbert re-entered the game.

It wasn't long before Herbert started looking like he was still in pain, though. The 24-year-old seemed to be moving gingerly during and after plays, and raised alarm bells at one point when he threw the ball away rather than run for an easy first down.

However, Herbert was also able to throw a 35-yard dart to wide receiver DeAndre Carter on the very next play, setting up a game-extending touchdown. Some athletes are simply built differently.

The Chargers' comeback ended up falling short when an onside kick didn't go their way on the ensuing kickoff, giving the Chiefs a 27-24 win in an entertaining start for the NFL's Amazon Prime "Thursday Night Football" era.

Herbert finished the game 33-of-48 for 334 passing yards, three passing touchdowns and a costly pick-six.

Brandon Staley says Justin Herbert is OK

When asked about Herbert's status after the game, Chargers head coach Brandon Staley told reporters the quarterback is "OK" and doesn't expect the rib injury to be an issue going forward, per The Athletic's Daniel Popper, though the team will know more on Thursday.

Herbert, who didn't speak with the media, received X-rays on the ribs after the game. Staley reportedly didn't sound too concerned, though. Why?

"Because he's Justin Herbert."