'Make people think': How the Cowboys plan to contain Brock Purdy and the versatile 49ers offense

FRISCO, Texas — Substitute goggles for helmets, and a microscope for a football.

But don’t let the Dallas Cowboys-San Francisco 49ers divisional playoff matchup mistake you.

Because in the eyes of Cowboys defensive coordinator Dan Quinn, this contest will feature a face off of mad scientists. 49ers head coach and play caller Kyle Shanahan stands opposite Quinn, who was Shanahan's boss when they coached together with the Atlanta Falcons. The Niners offense will threaten; the Cowboys defense will stage their counterattack. Rinse, repeat, diagnose, adjust.

“We kind of work in the same basement lab, just different sides of the same room,” Quinn explained. “Using the different players in different roles, the real mark of somebody who really knows how to attack. ... I do enjoy seeing from them the variety of the way they use the players.”

And on Sunday in an NFC divisional game pitting a rematch of teams who competed in the wild-card round last year, forget to which category of the depth chart players belong. Instead, expect San Francisco receivers aligning at running back, running backs as fullbacks, fullbacks at tight end and more. Expect Dallas safeties creeping into the box as linebackers, linebackers stepping up as defensive ends and edge rushers shifting over to defensive tackle.

Positionless football will abound. Coaches and players on each side of the ball expect their team’s best to emerge amid creative pressure.

The Cowboys have not faced a collection of weapons as versatile and talented as the 49ers this season. And the 49ers have not faced a defense as efficient or opportunistic as Dallas’.

“Best on best,” Cowboys All-Pro linebacker Micah Parsons said. “It’s really matchup against matchup.

“We’ve been working some things, so we get some disguised looks. Make people think…”

Can Cowboys prey on Purdy?

There’s one 49ers player in particular whom the Cowboys yearn to make think. This wouldn’t be the first time disguises muddied a rookie’s field of vision. And yet, after eight games playing the bulk of snaps as the 49ers quarterbacks … how inexperienced is Brock Purdy anyway?

“The three things that jumped out to me watching him and also getting a chance to watch him live lately is his instincts, his awareness and his confidence,” Cowboys coach Mike McCarthy said. “The awareness of defensive versatility, it doesn't seem to faze him. You don't see a young player making panicked decisions.

“He's not a rookie anymore in our eyes.”

Purdy has completed 67.1% of passes in his unlikely rise from last pick of the draft to rookie playoff victor, throwing for 1,374 yards, 13 touchdowns and just four interceptions in the regular season. Capitalizing on a deep stable of weapons, he played to an efficient 107.3 passer rating during the regular season. In a 41-23 wild-card win over the Seattle Seahawks last week, Purdy threw for 332 yards and three touchdowns, with a 131.5 rating and no mistakes.

The 23-year-old undoubtedly deserves credit for the success, which also speaks to the strength of Shanahan’s system.

Purdy has effectively distributed the ball to playmakers, including Christian McCaffrey, who ranked second in the league with 695 yards after the catch this season, and Deebo Samuel, who ranked 12th with 493. Add in George Kittle, one of two tight ends with double-digit touchdowns this season (Kittle had 11 to Kansas City Chiefs tight end Travis Kelce’s 12) and receiver Brandon Aiyuk, who led the team with 1,015 receiving yards, and the Niners have an embarrassment of riches.

The Cowboys, meanwhile, run the risk of embarrassment — especially should they bite at Shanahan’s menu of pre-snap motion, shifts and trickery.

“You really have to have great eye discipline,” Quinn said. “Having great eye discipline not only factors into the shift and the formation but holding your leverage onto the person where the ball goes, that’s a really big piece of it because they’ll attack you horizontally and also vertically.

“We’ve got to do what we do and kick ass at the highest fashion with our speed, with our takeaways, with our tackling. And really just play to our style. I’d imagine if we do that, we’ll let the results take care of themselves.”

‘Just switching the looks up’

The Cowboys defense already shuffled defensive responsibilities in Monday’s 31-14 win against quarterback Tom Brady and the Tampa Bay Buccaneers. Facing a pass-heavy team that relied heavily on drop-back passing, Dallas used at least three safeties on a season-high 78.8% of defensive snaps, per Next Gen Stats. On 15 plays, they used at least four.

The decision enabled the Cowboys to play with physicality and versatility, simultaneously covering for their lack of depth at cornerback while liberating defensive play callers to disguise applications. The Cowboys broke up 12 of Brady’s passes, denying the Buccaneers points on nine of 11 drives. This week, Quinn is likely to employ safety Jayron Kearse’s size-speed combination to take on Kittle’s danger, while safety Israel Mukuamu could similarly play in and out of the box.

Parsons, meanwhile, played more off-the-ball snaps (15) last week than he had throughout the regular season, when Dallas employed him as a pass-rusher more frequently. With the downfield and tackle-breaking threats San Francisco poses, his linebacking work could further ramp up. And if he does rush? Expect him coming from right and left ends both, as well as taking on offensive guards and tackles. The more opponents must account for his movement, the better.

As long as he’s heavily utilized, he’s happy.

“Just switching the looks up,” Parsons said of the strategy they used against the Buccaneers. “Five-man (rushes), four-man, get people to worry about the threat, the possibility of me coming, not coming, dropping into coverage.

“It don’t matter where we’re at. I feel like I can beat anybody.”

The more Parsons beats his matchups, the more likely the Cowboys beat the 4-point favorite 49ers. He said he doesn’t underestimate Purdy or his mobility, expecting the equivalent of a 12-round boxing match before either team advances. Doubt the Cowboys’ ability to stop the Niners’ high-octane offense?

Parsons welcomes that.

Quinn, too, returning to his lab.

“We hear, ‘No way the Cowboys are going to win. No way,’” Parsons said. “When no one believes in you, that’s the best feeling. Like now when everyone believes in you and the Kool-Aid is up and everyone’s smiling and they’re like, ‘They can’t lose. They’re too good,’ you don’t want that feeling because then it’s like, ‘Damn, what if I don’t win.’

“When you’re already at the bottom, you can only go up. So I really like being the underdog and that feeling. It’s a great story always to tell.”

Follow Yahoo Sports’ Jori Epstein on Twitter @JoriEpstein