But Arians isn't the type to blindly follow rules, and Mathieu engenders universal respect and admiration in Arizona's locker room.
"We have a little different bond, just because of where he came from, where I came from," Arians explained. "I've just gotten real attached to him. I love the player but I love the person more."
Arians wasn't alone in that sentiment for the team's most energetic and inspirational defensive force.
"He's such a valuable piece to this defense, this organization," general manager Steve Keim said early Monday morning.
"We're losing a brother and he's more than just that to this team, and this organization," safety Rashad Johnson said, via the team's official website. "He's a lifeline, he's an emotional leader. He plays with the passion and fire that we need every Sunday. When he's on the field, you know there is a different level of energy because of what this guy brings to the table. We're going to miss that. We all have to elevate our game."
NFL Media analyst Brian Baldinger, who raved about Mathieu earlier this month as "pound-for-pound the best player in the league," stated Monday that "there's simply no replacement for him right now."
"He's the energizer bunny. The guys love him. The preparation, how he tackles, how he plays the game," Baldinger added. "He's fierce, he's the best open field tackler in the league, he does it at 180 pounds. They love him."
Joining Baldinger on NFL Network's The Aftermath, Nate Burleson emphasized Mathieu's willingness to do what most defensive backs won't do.
"He's willing to cover anybody," Burleson said. "He'll cover your No. 1 -- the tall, speedy Calvin Johnson-type receiver. He'll cover your No. 1 if he's Antonio Brown. He'll cover your tight end if you put him in the red zone; it doesn't matter if it's Jimmy Graham or Rob Gronkowski. And then on top of that, he was this season the best blitzing cornerback in football. ... I just hope we all acknowledge the fact that he had a very special year."
Mathieu is ranked No. 1 among cornerbacks by the analytics site, Pro Football Focus. He's one of just three NFL players with at least 80 tackles and five interceptions this season. The most versatile defensive back in the league, Mathieu has lined up in the slot, at both safety positions and even at outside linebacker.
Palmer has compared Mathieu to a mix "right down the middle" between former All-Pro safeties Ed Reed and Troy Polamalu.
"He's all over the field. We ask him to do so much," Arians said back in October. "People don't realize how good a blitzer he is. He's a powerful little guy."
The coaching staff has given Mathieu so many responsibilities that it will take multiple players to fill the void. Arians confirmed Monday that Jerraud Powers will move into the nickelback role, with star special teamer Justin Bethel gaining snaps on the outside. A portion of his safety snaps will likely fall to hard-hitting D.J. Swearinger, who fared well as Johnson's replacement Sunday night.
Although it's a shame the "Honey Badger" will miss what has the potential to be a wild postseason ride, Arians is confident that his favorite player will embrace the challenge to return just as strong as he did after his previous ACL tear sabotaged a Defensive Rookie of the Year campaign in 2013.
"He'll be fine," Arians assured. "He'll bounce back, and he'll be ready for next year."