SEATTLE —

Let’s put the repeat talk on hold, OK?

Unless you are referring to the Seattle Seahawks turning in back-to-back quality performances, the R-word should be locked up somewhere in a back room of your vocabulary. The NFL season is too long and perilous, and this Seahawks team is not exactly a continuation of last season’s Super Bowl-winning squad. The Seahawks are different and developing, and the process is going to take time.

That message is clear now. The Seahawks lost three games all of last season. In 2014, they have already lost twice in their first five games, and the latest setback is quite concerning.

In the Russell Wilson era, the Seahawks have not been outplayed like they were in a 30-23 loss to the Dallas Cowboys on Sunday. The Cowboys came to CenturyLink Field and legitimized their strong early-season play by dominating the Seahawks statistically and having the guts to pull out a close game in the fourth quarter.

The Seahawks specialize in outlasting opponents, in punishing them physically and in winning tough games. They are used to administering thorough beatings and making the opponent surrender. They are used to watching other teams wilt amid the crowd noise and crazed atmosphere of their stadium.

But the Cowboys displayed toughness and resilience and won Seattle’s way. They dominated the time of possession and gained nearly twice as many yards as the Seahawks (401-206). Quarterback Tony Romo did not implode. Running back DeMarco Murray managed his sixth straight 100-yard rushing performance, gaining 115 yards on 29 carries. The Cowboys rushed for 162 yards, 100 more than the Seahawks’ stellar run defense had been allowing per game.

If the Seahawks had not dominated on special teams and capitalized on several Dallas mistakes, the game would not have been so close. On the concern scale, this registered higher than any recent Seattle loss.

“That’s a really tough ballgame,” Seahawks coach Pete Carroll said. “We make no excuses. (The Cowboys) played really well, and they did a lot of cool stuff for their football team in all phases, and we were not right, really, in any phase of our game.”

It is unprecedented for the championship-era Seahawks to play so poorly in a big game. They normally shine in these moments. Their competitiveness and preparation normally stand out.

Not this time. The Seahawks were not flat, but for the entire game, they were off. A bad pass here, a drop there. A missed tackle here, a third-down defensive breakdown there. A bad play call here, a bad play call there, a bad play call everywhere.

Maybe fans and followers have become spoiled by the Seahawks’ consistency. It was odd to see them so erratic. And now they have given an NFC upstart confidence. The Cowboys know they are for real, and they know they can beat the reigning champs.

For the first time in a while, you are looking at the Seahawks and wondering who the heck they are.

“It’s a hard lesson,” safety Earl Thomas said of the loss.

As much as the Seahawks already understood it would be difficult to wear a helmet and a crown this season, the challenge screamed at them Sunday. The Cowboys played their best game, just as San Diego did in Week 2. The Seahawks will continue to get every team’s best punch, and as the season progresses, they will learn how to counter better. But right now, they are still adjusting.

They have forgotten who they are on offense. Offensive coordinator Darrell Bevell is turning away from Marshawn Lynch too often, force-feeding Percy Harvin too much and focusing too little on balance, fluidity, and stretching the field in the passing game.

“Going into the season, we expected to do better,” wide receiver Doug Baldwin said. “We have a healthy Percy, so we expected more explosiveness from our offense. To not impact the game as much as we want to, as much as we think we’re capable of, is frustrating. No, we didn’t think it was just going to happen. But we expected better, for sure.”

This team can get better in so many areas. The pass defense is not where it was, including coverage and pass rush. The Seahawks are battling a rash of injuries, with concerns about the health of five starters. They are not playing with their trademark fire and swagger.

The Seahawks are still so good that, even at their worst, teams cannot separate from them. But the carefree team with unlimited depth from 2013 now has a thinner roster carrying the burden of expectations.

“I think everybody is a little frustrated,” said Wilson, who completed only 14 of 28 passes for 126 yards.

It is too early to be outraged. The Seahawks have plenty of time to thrive. But they are learning why it is so hard to repeat in the parity-driven NFL. And this is why the Seahawks must block out the ultimate goal for now and focus simply on getting better.

Sunday was sobering. The competition is not catching up. The competition is right there, stride for stride.

Such is life in this league, where dominance is fleeting and a reigning champion is merely a target.

Jerry Brewer is a columnist with the Seattle Times.