Over the last several seasons, the debate has been “what is a catch?” Now, it may become “what is a legal tackle?”

The NFL has instituted a new policy ahead of the 2018 season that has been referred to on social media as the “helmet rule,” which has caused a bit of an uproar over the first two weeks of the preseason.

During the New York Giants’ 30-17 win over the Detroit Lions at Ford Field on Friday night, linebacker Mark Herzlich was called for unsportsmanlike conduct and penalized 15 yards under the guise of this new rule.

When you look back at the replay, it clearly shows that Herzlich did nothing wrong and never lead with his helmet, which is what the rule aims to eliminate.

On Saturday, Giants head coach Pat Shurmur declined to offer his take on the rule or the Herzlich penalty because he wasn’t interested in writing a fresh check to league this early in the season.

“I don’t think it’s necessary to get fined in the preseason,” Shurmur told reporters during a conference call.

Shurmur said that he will be sending the NFL the replay of Herzlich’s penalty — one that negated a sack by rookie linebacker Lorenzo Carter — seeking an explanation.

“I have a very strong opinion of that play. We’re going to send that play in to get evaluated and we’ll see what they say, and what they do tell me, I won’t tell you,” Shurmur said. “Here’s the thing — we want to teach a physical, safe game, played by the rules, and things happen fast in games, and we all certainly see things differently in real speed, so sometimes it gets left to interpretation when you replay it in HD very slowly, so we’ll just see. Part of the preseason is everyone getting used to the new rule. Not only how to play the game, but how to officiate it; and I’m hopeful I’m going to get an answer on that play.”

If the penalty against Herzlich is a sign of things to come with the NFL, then Commissioner Roger Goodell better be ready for a flurry of complaints from every direction because the rule is restricting what players on defense naturally do in the midst of a boom-boom play.