ARLINGTON, Texas -- The defense believed they could get a stop. They looked at each other, confident. This was the position they wanted to be in -- game on the line, needing to contain Dak Prescott and Ezekiel Elliott to wrap up a needed road win.

Then the plays started. And the Detroit Lions, as they've shown in three of four games this season, struggled to stop much of anything. So many of the concerns about Detroit's roster before the season showed up in the final drive in Dallas. The Lions couldn't rush the passer. They couldn't cover opposing tight ends or running backs.

That cost them, as Dallas drove down the field to kick a game-winning field goal as time expired, giving the Cowboys a 26-24 win over Detroit. In doing so, it brought back all those issues a week after the Lions looked good defensively against New England.

"Our biggest thing is we've got to close," defensive lineman Ricky Jean Francois said. "That's our thing. We've got to close out. We can't keep killing ourselves with penalties, can't keep killing ourselves with missed assignments, can't keep killing ourselves with missed tackles. I'm only talking from our side of the ball, not the offense. We have to do better.

"Like our offense is rolling. You see our offense. Matt [Stafford] got the team running. [LeGarrette] Blount got the ball running, well, all our backs got it. So now it's like, it's on us. We got to get this job done. It's not the coaches. It's us, as players, we got to get the job right."

But what if they can't? What Detroit looks like four games into this season is this: A potentially dynamic offense with one of the best receiving tandems in the NFL and a defense that is going to force the offense to play that much better to secure wins. And that's what we thought this Lions team might be.

How else can you explain how Prescott, who had yet to throw for more than 200 yards this season, completed 17 of 27 passes for 255 yards? Or how Elliott, as good as he might be, had 240 yards of total offense when it's clear he is the focal point of the Cowboys' attack?

Once again, the Lions went to their typical post-loss buzz phrases: lack of execution, being more detail-oriented, cutting down on the mistakes, just needing to play better. They all said it has nothing to do with the scheme. They believe they have the right players.

Yet, it's not coming together with consistency -- something the Lions had a chance to show by making the last-minute defensive stop that they failed to execute.

"Offense put us in a good situation. It's a team game," cornerback Jamal Agnew said. "They put us in a good situation to go close the game out. We didn't execute as a defense."

That's what left linebacker Jarrad Davis, who gave up a critical 34-yard reception to Elliott, emotional after the game. It's what left other Lions players facing the same defensive questions they have the past month.

Why does this defense continue to struggle?

"It's just consistency," Davis said. "You just got to be consistent. You got to come out every single day and you got to know that this is what we got, this is what our issues are. This is what this team likes to do.

"We've got to be consistent in stopping them and consistent in not making our own mistakes, you know."

And yet, that inconsistency has shown up almost every week. It left Davis saying that he's "not sure" why it keeps happening. Same with linebacker Christian Jones. The issues seem obvious, though.

Detroit, minus Ezekiel Ansah, doesn't have a consistent playmaker on its defensive line. Its linebackers struggle in coverage. Detroit's first two opponents, the Jets and 49ers, exposed outside runs as a problem for the Lions. They've improved there the past couple weeks, but they're still an issue.

Until the Lions solve that issue, teams are going to exploit it because masking and scheming can only do so much.

"We've seen all the stuff we can do good and well. Now we need to pay attention," Jean Francois said. "But at the same time, look at all the stuff we do bad because now teams are finding tendencies about us that they keep running -- it's like from Week 1 to Week 4, everyone is going to run the same thing. They're not going to change nothing until we defeat what's beating us.

"So as players we got to come together. The coaches they can talk 'til they're blue in the face, come up with all type of riddles and puzzles, but that's not going to do anything for us. We as players got to step up and show the NFL -- not our coach, show the NFL -- that we can actually play ball. We can play teams from the first to the fourth quarter."

They've shown that this year in spurts, but not enough to be reliable.

Yet Detroit still believes these things can be fixed this season. Lions coach Matt Patricia said he's "not discouraged" by any of the Lions' defensive problems. And for the second time in a month, Detroit's defenders have echoes the cliché of needing to look in the mirror to figure out their problems.

Through one month, Detroit hasn't been able to do that all too often. And even though there is a lot of time left, there's a sense that with the Bears surprising, the Packers returning to form and the Vikings potentially lurking, any defensive issues the Lions have need to be solved.

Fast.