The Minnesota Vikings spent the week preparing to face Dak Prescott rather than Dallas Cowboys backup quarterback Cooper Rush, with their starter hoping to return in Week 9 after they survived his absence.

Prescott's status for Sunday's game, which the Cowboys went on to win 20-16 on the road, had been uncertain in the days leading up to the contest due to his calf injury.

He was ultimately ruled out after undergoing tests in the pre-game warmup, allowing Rush to make his first career NFL start.

Despite only completing 24 of his 40 pass attempts, Rush still racked up 325 passing yards and two touchdowns to one interception.

He threw a go-ahead touchdown pass to Amari Cooper, who starred with eight catches and 122 receiving yards, in the final minute as the Cowboys improved to 6-1 even without star QB Prescott.

Asked about how the Vikings had prepared for the possibility of facing Prescott or Rush this week, safety Xavier Woods acknowledged they expected the more senior player to take the field.

"We weren't [preparing for both]," said Woods, per ESPN. "We were just preparing for 4 [Prescott].

"We kind of thought they were going to still run the same offense. So, we just prepared for 4 all week. 

"We didn't get the word [that Rush was going to start] until pregame, so we just prepared for 4 but we watched a couple clips of Coop. But during the week, we just prepared for 4."

CeeDee Lamb (eight catches for 112 yards) and Cedrick Wilson (three catches for 84 yards and one TD) also proved productive targets for Rush.

The Cowboys hope Prescott can return for the home game with the Denver Broncos, though they are eager to ensure his injury heals fully in a season where a playoff run looks increasingly likely.

Asked if facing Denver was possible, Prescott said: "For sure. I was getting prepared to play this game

"I'm a guy that takes it day-by-day, moment-at-moment, and right now, I'm going to celebrate this win with the guys and worry about rehabbing and getting everything back in order on Monday.

"We made a call at the end of having a chance to come out with a win, without me playing, and be able to get healthy and not have something re-injure and linger past this week."

After a slow start, which included an interception by Woods and Dallas' first pointless first quarter of the season, Rush delivered with a game-winning drive in the closing stages.

"That's Coop," added Prescott. "He's very mild tempered and always that way – never too high or too low. It showed.

"It allowed him to stay in there, stick to it, stick through some bad plays and come out and make some great plays to win the game that we needed in the fourth quarter."

Rush became the first quarterback to throw 300-plus passing yards and win in his first NFL start in a primetime road game since 1984.

Minnesota, meanwhile, fall to 3-4 and have a testing road game with the Baltimore Ravens (5-2) in Week 9.