CHARLOTTE – Before Sunday, the Panthers hadn't allowed a 100-yard rusher since Bills running back C.J. Spiller gained 103 yards in Week 2 of the 2013 season.
A pair of Pittsburgh running backs ended that streak. Le'Veon Bell compiled 147 yards and LeGarrette Blount totaled 118.
Will Sunday's performance prove to be an outlier for Carolina's typically stout rush defense?
"We hope it is," defensive coordinator Sean McDermott said. "But at the same time, it's something that, if you don't get corrected, can fester. We have to play more physical, make sure we are getting off blocks, use our hands and play tough defense.
"Give them credit, they came in and did a good job. We didn't play or coach up to our abilities."
To return to form, Carolina must learn from a humbling defeat. McDermott is confident his unit, which surrendered 30 or more points just once last season, will respond appropriately.
"Sometimes, we learn more from losses than we do from wins," McDermott said. "I'm hoping that's the case in this situation. It's where we go from here that matters the most.
"I expect the response to be what it's been in the past. We've been through situations like this and we've learned from them. We've got to learn from this and move forward. This will help us come together as a defense and as a team."
RUNS MUST INCREASE: How do the Panthers improve their running game, which ranks 29th in the NFL after three games? It starts by running it more often.
"First of all, we can't expect to win many games running the ball 10 times, I want to say that," offensive coordinator Mike Shula said. "We are going to have to run the ball and have good balance – better than we had (on Sunday).
"The game dictated a little bit of that. Some long-yardage situations did, too, but I don't want to use those as excuses," Shula said. "We have to run the ball more. I have to call more runs."
Carolina ran the ball a franchise-low 10 times for 42 yards in the loss to the Steelers. Running back Jonathan Stewart led the team with five carries for 31 yards.
Shula has consistently emphasized his desire for a balanced approach, running 48.3 percent of the time and passing 51.7 percent of the time in 2013. That formula was a key to success, as Carolina ran for more than 100 yards in 14 out of 16 games.
After consecutive weeks in which the Panthers have failed to rush for 100 yards, achieving that balance going forward tops the list of priorities, even if defenses stack the box to stop it.
"Everyone talks about running against the extra guy and all that. There are a lot of times where teams run the ball successfully with an extra guy unblocked – and we are one of those teams that has done that in the past," Shula said. "We can't get deterred by teams loading up the box."
The Panthers rushing attack has also been impacted by quarterback Cam Newton's current physical limitations. Newton – the only quarterback in NFL history to rush for 500 yards in each of his first three seasons – ran the ball just twice on Sunday, a career low.
That number isn't surprising considering Newton is battling ankle and rib soreness, but Shula expects to gradually utilize Newton's legs more as the season progresses.
"We are going to keep monitoring him and keep working it to where we can work him into more of the running game," Shula said. "We will pick and choose our spots. It's one of the best things he does. He's really good at it.
"Just because he is a little beat up doesn't necessarily mean we are going to eliminate him running the football. But we have to be smart about it."