“I’ve rested players, I’ve not rested players,” said McCarthy, who previously coached the Green Bay Packers for 13 seasons. “But we felt where we were as a team, our first year in the playoffs, it was important for us to play.”

It was important for Prescott, who looked comfortable dissecting the Eagles’ defense, completing 21 of 27 passes for 295 yards. It was important for receiver Cedrick Wilson, who, with Michael Gallup out for the season with a torn knee ligament, continued his emergence as a dependable third receiving option, catching five passes for 119 yards and two touchdowns. And it was important for running back Ezekiel Elliott, hampered with a knee injury much of the season, who gained 87 of Dallas’s 171 rushing yards then proclaimed himself healthy for the postseason.

The Cowboys scored on eight of nine possessions, excluding kneel-downs, and for a rivalry so steeped in antipathy, with tales of Bounty Bowls and pickle juice and flying pork chops, this installment featured all the excitement of a beige sofa.

As Dallas traveled without linebacker Micah Parsons, left tackle Tyron Smith and running back Tony Pollard, among others, Eagles Coach Nick Sirianni opted to rest 16 starters — not including center Jason Kelce, who played only the first snap, just to extend his consecutive-start streak to 122 — and elevated 12 players from the practice squad.

Under Sirianni, Philadelphia’s first-year head coach, the Eagles more than doubled their victory total from last season’s 4-11-1 fiasco, throttling bad teams and backup quarterbacks with a run-heavy offense led by quarterback Jalen Hurts to win six of their final eight games. Still recovering from a high ankle sprain, Hurts sat Saturday in place of Gardner Minshew, but Sirianni said he will be ready for the Eagles’ playoff game.

The only way Philadelphia can rise to sixth from seventh in the N.F.C. is if New Orleans defeats Atlanta and the Rams beat San Francisco. The Cowboys, as N.F.C. East champions, won’t fall below fourth but could move as high as second.

Either way, they will host a playoff game, and though everyone from Prescott to McCarthy to DeMarcus Lawrence emphasized their second-by-second focus heading into next weekend, it did not require much imagination to recognize that the Cowboys, with a first-round victory, could wind up facing the top-seeded Packers, in frigid Green Bay, Wis.