Some of the best defenders in the NFL suddenly have no idea how to tackle the quarterback anymore

• Chiefs defender Chris Jones received a questionable flag for roughing the passer on Monday night.
• Watching the hit from home, several legendary NFL defenders chimed in, expressing confusion.

NFL defenders are openly questioning how they're supposed to bring down opposing quarterbacks after two controversial roughing-the-passer penalties were called over the weekend.

On Sunday, Falcons defender Grady Jarrett was flagged after what looked like a textbook sack on Tom Brady. The penalty helped secure the win for Brady and the Buccaneers.

If it had just been the one penalty, NFL fans could have chalked it up to Brady earning a veteran call, but on Monday night, a similar situation played out in Kansas City, when Chiefs defender Chris Jones was flagged after a strip sack on Raiders quarterback Derek Carr.

The penalty flag earned loud boos for the referees for the rest of the night, as well as more than a couple make-up calls later in the game. Ultimately, the Chiefs prevailed 30-29, so Kansas City sent the home crowd home happy.

But the penalty still left one big unanswered question: What exactly is a defender supposed to do if he makes it to the quarterback in the backfield?

It wasn't just fans asking the question, as several of the greatest NFL defenders of all time, as well as current talents, added their thoughts on Twitter.

Referee Carl Cheffers said after the game that he was only applying the rules as written.

"The quarterback is in the pocket, and he's in a passing posture. He gets full protection of all the aspects of what we give the quarterback in a passing posture," Cheffers explained. "So, when he was tackled, my ruling was the defender landed on him with full body weight. The quarterback is protected from being tackled with full body weight. My ruling was roughing the passer for that reason."

The "full body weight" issue of the hit was also subject to scrutiny, as Jones had appeared to put his arm out to ease his fall on top of Carr, but once a call like roughing the passer is made, it is final.

After the game, Jones himself offered a reasonable half-measure that could have helped: Make roughing-the-passer penalties subject to review.

"With roughing the passer, they've put such an emphasis on it, that we've got to be able to review it in the booth," Jones told reporters in the locker room. "I think that's the next step for the NFL as a whole. If we're going to continue to call roughing the passer at that high of a velocity, then we've got be able to review it in the booth to make sure, because sometimes looks can be deceiving. From a ref's point of view, it probably looked like that initially, but when you look at the replay, it's a whole different thing. "

While making the penalty reviewable sounds good in theory, it also adds another layer of bureaucracy to NFL officiating, which we know from experience can come with unintended consequences. Remember a few years ago when pass interference could be challenged? How did that work out?

That said, the NFL is clearly trying to better protect their quarterbacks, and in the wake of Dolphins QB Tua Tagovailoa's concussions and the renewed attention brought to player safety, there were going to be some bumps along the way.

For now, NFL defenders are faced with a tough task — break through the offensive line and get to the quarterback, but please be gentle along the way.