This applies to 49ers quarterback Colin Kaepernick, as well.
Read option or not, Green Bay's defense hopes it plays much better Sunday in San Francisco than in the last game it played that counted, run out of town and out of the playoffs in January by Kaepernick and the 49ers.
"I mean, anytime a runner — if you're playing defense — is running the ball, the goal is to hit him as soon as possible," McCarthy said when asked if Kaepernick would have to "earn" his yards in the season opener at Candlestick Park. "I think that would hold true for any offensive player."
Sounds simple enough. The Packers just need to do a much better job of it this time around.
Kaepernick's breakout game came in his first career playoff start only two months after winning the 49ers' starting job. San Francisco beat Green Bay 45-31, with Kaepernick running for a pair of touchdowns and throwing for two more. He set a quarterback playoff record in the process with 181 yards rushing.
Since then, the likes of mobile quarterbacks including Kaepernick, the Redskins' Robert Griffin III and the Seahawks' Russell Wilson have stirred more discussion of the dos and don'ts of hitting a quarterback outside the pocket.
San Francisco coach Jim Harbaugh on Wednesday said he had been hearing a "lot of tough talk right now, you're hearing some intimidating talk."
Added Harbaugh at the 49ers' facilities in Santa Clara: "It sounds a lot like targeting a specific player. You definitely start to wonder. A man will usually tell you his bad intentions if you just listen. You know what's being said publicly, not what's being said privately. You hope that their intent isn't going to be anything that's not within the rules."
Perhaps comments earlier this week in separate interviews from Packers linebacker Clay Matthews, about hitting the quarterback, got Harbaugh's attention. Matthews steered clear when asked Thursday if he was surprised by Harbaugh's comments.
"I'm really focused on what this locker room has to say as well as the men in here," Matthews said. "I think we're just ready to play the game."
But there might still be questions in knowing when it is and isn't OK to hit. On Thursday, an NFL officiating video to media covered read option situations.
The basic premise: if a quarterback is running, or in a "running posture," then he's subject to normal unnecessary roughness rules, but not roughing the passer.
Dean Blandino, the NFL vice president of officiating, said on the video that "the quarterback position is not defenseless throughout the down ... it's the posture he presents that will dictate his protections."
McCarthy praised the NFL for keeping teams educated and updated on rules, including visits from referees.
"We'll find out," Matthews said when asked about a "gray area" in how it might be called. "The natural progression of the game with quarterbacks who continue the play-fake, we'll see. But we feel good about our scheme and what we're going to try to accomplish."
McCarthy broke it down simply again when asked if it was OK to hit the quarterback if the quarterback was carrying out a fake.
"The reality is, the quarterback is part of the option," he said. "There (are) three options obviously: the quarterback, the dive and the pitch. The ability to go tackle that player is obviously within the rules."
The Packers will be without cornerback Casey Hayward, who re-aggravated a hamstring injury two weeks ago during the preseason. Another defensive back, special teams ace Jarrett Bush, was limited in practice Thursday with an ankle injury.
But there's optimism in Green Bay about the pass rush, especially with Matthews leading the charge. The defensive line has added Johnny Jolly, following three years away for off-field issues, and first-round draft pick Datone Jones.
Defensive lineman B.J. Raji feels things will be different Sunday, though he plans to put more stock in the results.
"I doesn't matter what I think, it's how I play and how we play. I believe we'll play better," Raji said. "That'll be the difference."
Find Genaro Armas on Twitter at twitter.com/GArmasAP.