CHARLOTTE, N.C. – Even when Green Bay Packers defensive players think they know what’s coming, they can’t stop it.

That’s the sad reality for a defense that once again has let down a team with legitimate Super Bowl aspirations.

Consider the pre-snap exchange between Packers linebacker Clay Matthews and Panthers quarterback Cam Newton that was audible on the Fox broadcast during Sunday’s game at Carolina.

Cam Newton.changed the questions when Clay Matthews and the Packers thought they had the answers. Streeter Lecka/Getty Images

Matthews thought he knew what was coming and alerted his teammates.

“It’s that wheel route,” Matthews shouted. “It’s that wheel route.”

It sounds like Matthews was correct.

“You’ve been watching film, huh?” Newton replied.

And then he apparently made an adjustment.

“That’s cool,” Newton said. “Watch this.”

It wasn’t a wheel route – a pattern in which a running back, in this case Christian McCaffrey, curls toward the sideline and then breaks vertically up the sideline. Instead, McCaffrey faked the wheel route and broke inside on a slant for an easy 7-yard touchdown in the Packers' 31-24 loss.

But here’s the thing that should be most troubling to the Packers: The wheel route was wide open, too, even after Matthews called it out.

It was just one play, but it’s a microcosm of the breakdowns the Packers have experienced far too often on that side of the ball.

The Panthers had another uncontested touchdown on the opening drive on the third quarter, when rookie safety Josh Jones let tight end Greg Olsen get behind him after Jones inexplicably bit up without help behind him. It turned into a gimme 30-yard touchdown pass for Newton.

“Just couldn’t get off the field on third down,” Packers coach Mike McCarthy said. “A couple penalties, discipline penalties, no excuse for that. But their key players, McCaffrey, Olson, we didn’t do a good job limiting their production. They had some big plays.”

What was supposed to be a bounce-back year for a Packers’ defense that ranked 31st in the NFL against the pass last year has turned into more of the same. Defensive coordinator Dom Capers’ unit ranks 26th in yards allowed per game (356.4), 21st against the run (116.4 yards per game) and 24th against the pass (240.0).

McCarthy will have to decide this offseason whether the problem was with personnel and/or injuries or Capers’ game-planning and/or play-calling.

Capers has been the Packers’ defensive coordinator since 2009 and is only the second coach to hold that job under McCarthy, who fired Bob Sanders after the 2008 season – the last time the Packers did not make the playoffs.

Capers has survived despite coordinating a defense that in 2012 gave up 181 yards rushing to Colin Kaepernick in a playoff game, in 2014 collapsed in the NFC Championship Game at Seattle, in 2015 couldn’t stop Larry Fitzgerald in an overtime playoff loss, and last season got exposed by Matt Ryan and Julio Jones in the NFC title game loss at Atlanta.