MINNEAPOLIS — Dak Prescott jogged off the field at U.S. Bank Stadium after a 38-minute pregame workout Sunday. The extensive warmup didn’t change the Cowboys’ reality: Dallas will face the Vikings on “Sunday Night Football” without their starting quarterback.

Prescott is inactive, the team confirmed 90 minutes before kickoff.

Fifth-year pro Cooper Rush, who has attempted three passes in his entire career, will instead make his first NFL start.

The Cowboys first signed Rush in 2017 as an undrafted free agent out of Central Michigan. He spent three years as Prescott’s backup, rejoining the team last year after Prescott’s injury. He knows the system and his teammates closely, but has scant regular-season experience.

Rush has attempted just three passes in his NFL career, completing one in a 2017 contest. He rushed twice in that contest for 13 yards. Teammates and coaches express confidence in what Rush could do surrounded by weapons and protected by what Pro Football Focus ranks as the league’s top offensive line. Even so, he’s far from demonstrated Prescott’s acumen.

Prescott led the Cowboys to five straight wins and has completed 73.1% of his passes for 1,813 yards, 16 touchdowns and four interceptions.

Prescott’s availability for the “Sunday Night Football” contest was in doubt two weeks after he strained his calf. The quarterback was limited in practices this week coming off the bye, and the 5-1 Cowboys’ cushioned NFC East led further strengthened the cause for caution. Another lingering concern: the calf strain’s connection to Prescott’s 2020 compound fracture and dislocation of his ankle—both injuries on the lower right leg.

Then came warmups on the U.S. Bank Stadium turf, Prescott cycling through footwork without visible mobility restrictions. But this decision wasn’t Prescott’s alone, nor was it about how his play looked. Super Bowl hopes float through the Star, and the quarterback’s long-term availability was deemed more important than a Week 8 win.

“There’s no question he’s going to be the most pro person on the planet to play,” Cowboys owner/general manager Jerry Jones said of Prescott’s desire to compete. “I think he’s aware of what’s at stake here and what’s the future.”

Veteran journeyman Will Grier, whom Dallas claimed off waivers this fall, will back up Rush.

Cowboys running back Ezekiel Elliott expressed confidence in Rush’s poise and play.

“He is a baller,” Elliott said. “He knows this offense, he is confident and he can play.

“If his number is called, he will be ready.”

The Cowboys enter Minnesota averaging a league-best 34.2 points and 460.8 yards per game. 

Follow USA TODAY Sports’ Jori Epstein on Twitter @JoriEpstein.