ARLINGTON, Texas — It's another loss for the Dallas Cowboys against a team in the playoff picture, and they're left yet again to wonder if they're actually being defeated by the opponent in 2019, or if they are, in fact, their own greatest enemy.

They got off to another slow start in Week 10 against the visiting Minnesota Vikings, coming up empty on an opening drive that included a missed 57-yard field goal by Brett Maher, and then did nothing defensively to stop themselves from falling into a 7-0 hole that then grew to a 14-0 deficit before the first quarter was in the books. Offensively, they'd come alive on the arm of quarterback Dak Prescott, who went on to throw for 396 yards and three touchdowns; with his lone interception occurring on a Hail Mary as he tried one last time to save the day in the 28-24 loss to the Vikings.

All in all, Prescott -- with the aid of a 147-yard, one touchdown effort from Amari Cooper; a redemptive 106-yard, one touchdown outing by Randall Cobb; and an impactful 76-yard, one touchdown game by Michael Gallup -- was master class for much of the game. But the problem was clear in that it wasn't the offense giving up the goat on "Sunday Night Football".

It was the defense, who caused the Cowboys to lose the time of possession battle by nearly eight minutes, and allowed running back Dalvin Cook to blast off with 183 yards from scrimmage and a touchdown.

"We didn't play well as a group [defensively]," Sean Lee said. "It starts with a guy like me. I didn't tackle well. We started slow, and we need to be better as a group ... We're going to look at this game and be disappointed at how we played defensively. I think our offense did a great job and kept us in the game. We just have to find a way to get off the field. We can't let a team run like that. 

"You're not going to win like that."

He's correct, and that's why they didn't.

"Defensively, we put [Prescott] in a bad position over and over again, by not getting off the field and not stopping the run," Lee continued. "We need to step up in a game like that, and didn't."

As for the future, with seven games remaining in the regular season, the Cowboys are now tied with the Philadelphia Eagles atop the NFC East, and will head north to face the Detroit Lions in Week 11. Things won't suddenly become forgiving for their schedule going forward, with a meeting against the New England Patriots thereafter, followed by a clash with a Buffalo Bills team on Thanksgiving that is wholly unpredictable on any given week.

"I think we're still game-to-game, and we still have a lot ahead of us," Lee said. "We want to start winning games like this -- against teams with good records. Defensively, we're going to have to play better if we want to do that. I think we can execute better. ... I still think we're a team that can play with anybody, and beat anybody. We just need to show that more consistently."

All-Pro pass rusher DeMarcus Lawrence, who had eight combined tackles in the loss to the Vikings, agrees.

"[The losses are] our fault," Lawrence said. "We need to clean up the execution and the fundamentals, and that's it. Get to the football, wrap up and tackle."

Yes, but are the Cowboys still a Super Bowl contender, assuming they stop shooting themselves in the foot?

"Absolutely," Lawrence told me. "If we stop beating ourselves, understand the game plan and go execute? S---, we'll be there."