Will the 49ers’ game plan expose an unsolved weakness for the Cowboys?

While climbing from 6-10 in Mike McCarthy’s first year to a 12-5 record this season, it would appear the Cowboys improved in every significant area. As their playoff date with the 49ers approaches, I’m still wondering about a particular soft spot from a year ago and whether it truly has been fixed.

You know how bad Dallas was against the run in 2020. Record-setting bad. Cleveland broke a 20-year-old record against the Cowboys with 307 yards rushing in October. Baltimore tried to break that one with 294 more in December. For the year, opponents averaged a hefty 5.0 yards per carry. Only two defenses fared worse.

In 2021, opponents have not chewed up the Dallas defense with their running attacks as San Francisco will try to do here Sunday afternoon. But what is the reason for that? Is it because miracle-working rookie linebacker Micah Parsons has fixed everything? Or is it because the Cowboys were never really challenged?

Dallas ranks sixth among the seven NFC playoff teams in rushing yards allowed per game. Only Arizona gave up more. The club is 16th in the league, in part because when you score 40 or more points four times you’re probably not facing a lot of rushing attempts. The Cowboys still surrendered 4.5 yards per carry this season to place them outside the top 20.

That’s not good.

And that’s in spite of the fact that, of the top 10 backs in rushing yards per game, Dallas faced only one. The Cowboys did a reasonable job against Minnesota’s Dalvin Cook (18 carries for 78 yards) in a 20-16 win over the Vikings in October. They caught a break when they didn’t face Alvin Kamara in New Orleans. Carolina’s Christian McCaffrey was injured the week before the Panthers came to Dallas. The schedule provided the Cowboys with five AFC opponents, none of whom featured a back in the top 15 in rushing yards per game.

Then there was the weird case of the Philadelphia Eagles, a team that set its own club record with more than 2,700 yards rushing, leading the league in that category. But the Cowboys played them in September before rookie coach Nick Sirianni had figured out who they were. Eagles running backs had three carries in that game. When they met again Saturday, Philadelphia had clinched its wild-card spot so Miles Sanders, Boston Scott, Jordan Howard and (most important of all) Jalen Hurts sat out the game.

But did anyone notice the alarm bells sounding for the Cowboys during that 51-26 destruction of the Eagles? Or was that just me?

Rookie Kenneth Gainwell and practice squad back Jason Huntley ran 25 times for 129 yards. Now the Cowboys were missing Parsons and other starters, too — though not nearly as many as Philadelphia — and it was a blowout win, so maybe there was a bit of a “who cares’' nature to those rushing yards. I suspect we will find out Sunday at 3:30.

“Our key is stop the run and then let the monsters eat on third down,’’ said Parsons, a self-proclaimed but proven monster himself. “You’ve got to win the first and second down.’’

On Sunday, that will mean plenty of run-stuffing. San Francisco coach Kyle Shanahan commits to the run harder than just about any coach you will find these days.

That’s funny given that in his last game as an offensive coordinator for Atlanta, he famously managed to turn a 28-3 lead over New England into defeat mostly by failing to back off the Falcons’ potent passing attack.

On the game-tying third quarter drive against the Rams Sunday, a game the 49ers had to win to make the playoffs, San Francisco ran the ball 10 straight times for 50 yards. That will break a defense’s spirit. Then wide receiver Deebo Samuel, who has been averaging more than six runs per game the last eight weeks, took a handoff from Jimmy Garoppolo and tied the game with a 24-yard touchdown pass to Jauan Jennings.

Elijah Mitchell is now the man for the 49ers. Shanahan favored a rotation of backs for several years in San Francisco, even when the team went to the Super Bowl after the 2019 season. But Mitchell was fifth in the league in yards per game, chalking up more than 100 yards in five of the 11 games he played. In his last five starts, Mitchell has not had fewer than 21 carries. In other words, he is asked to do what almost no NFL backs are asked to do anymore.

Are the Cowboys ready to stop this?

The game against Dalvin Cook suggests maybe yes. Some of their season-long numbers suggest maybe no.

It always helps to get a lead, and the Cowboys have been outstanding on that front. But don’t expect Shanahan and Mitchell and even Samuel to stop running right at them if the Cowboys get a lead. After a 7-2 sprint that featured two wins over the Rams and one against Cincinnati, the 49ers know how they got to the playoffs. They know what works for them. It’s up to the Cowboys to prove their issues against the run are dead and buried.

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