Ryan Clark and Chris Mortensen react to Dolphins DE William Hayes tearing his ACL while trying to avoid a penalty after sacking Raiders QB Derek Carr. (1:35)

DAVIE, Fla. -- Miami Dolphins defensive end William Hayes tore the ACL in his right knee on Sunday in an unusual way.

It happened while Hayes completed a huge third-down sack on Oakland Raiders quarterback Derek Carr, coach Adam Gase said.

"He was trying to not put body weight on the quarterback," Gase said. "His foot got caught in the ground."

According to a new NFL point of emphasis, a defender "is responsible for avoiding landing on the quarterback when taking him to the ground." Violating the rule results in a 15-yard roughing the passer penalty.

When asked whether he believes the rule change led to Hayes' torn ACL, Gase said, "I'm just telling you what happened. ... I'm just telling you what he did."

San Francisco 49ers cornerback Richard Sherman tweeted that Hayes' injury proves the NFL only cares about the health of its quarterbacks.

They don't care about the rest of us getting hurt. Long as the QB is safe https://t.co/ihjlz3lVQl — Richard Sherman (@RSherman_25) September 24, 2018

"It sucks because he was trying to protect the quarterback while still trying to make the play, and it's a double-edged sword," Dolphins defensive lineman Akeem Spence said Monday. "What do you expect us to do? We know the rule, but we don't know the ins and outs. And then I saw Clay Matthews, he had another one yesterday. What do you want the guy to do? You gotta put the guy down. How much is too much weight? What technique do you use? How do you go about it? We are still asking questions just like y'all are.

"Let's be honest, that's a difficult rule to gauge."

Hayes appeared to shorten his last step -- with his right leg -- and attempted to roll over Carr instead of landing on him. He immediately grabbed his right knee, rolling and crawling on the ground while his teammates tried to help him.

William Hayes tried to avoid putting his body weight on Derek Carr on this sack and ended up tearing his ACL when his foot got caught in the ground, Dolphins coach Adam Gase said. AP Photo/Lynne Sladky

Hayes walked off the field in considerable pain with a heavy limp.

This is a big loss for the Dolphins, who counted on Hayes to be one of their top run stoppers and rotational edge rushers.

"It hurts. He's one of our leaders," Gase said. "That's going to be a tough one to swallow."

Charles Harris, the Dolphins' 2017 first-round pick, will be asked to step into a bigger role with Hayes out.

Gase did confirm Monday that injuries to defensive end Andre Branch (knee), linebacker Chase Allen (foot) and tight end A.J. Derby (foot) are not expected to be season-ending.