The Cowboys and quarterback Dak Prescott had a rough outing in a season-opening loss to Carolina. (Mike McCarn/Associated Press)

The first Sunday of the 2018 NFL season is done, and there is plenty to digest.

The first tie game since the league shortened overtime to 10 minutes ahead of last season revealed something about the Cleveland Browns, who aren’t dreadful, and about the Pittsburgh Steelers, who need Le’Veon Bell back no matter how many yards James Conner produced running in Bell’s place. Aaron Rodgers reinforced just how ridiculously great he is with another dose of quarterbacking wizardry for the Green Bay Packers that overcame the defensive dominance of Khalil Mack in his Chicago Bears debut.

And there was more, much more.

The first Monday of the NFL regular season, naturally, is the biggest overreaction day on the sport’s calendar. Sweeping conclusions about a team or a player usually can’t be drawn after one game, at least not justifiably. But sometimes, that one game can serve as a harbinger of what’s to come. The trick is figuring out which is which.

Here’s a quick attempt to distinguish which teams (and their fans) should be rightfully fretting at this point and which shouldn’t.

Teams with legitimate reasons to worry …

Buffalo Bills: Why, exactly, were the Bills so eager to get rid of quarterback Tyrod Taylor in the offseason? They were a playoff team last season with Taylor. Now, having dispatched him to Cleveland, they appear to be a mess. The Bills gave up on would-be temporary starter AJ McCarron before the season even arrived and dealt him to Oakland. They keep giving starting chances to Nathan Peterman, and it keeps going badly. On Sunday, Peterman wasn’t five-interceptions-in-a-half bad, as he was last season. But he was bad, as the Bills went without a first down in the opening half en route to a 47-3 defeat. Prized rookie Josh Allen made his NFL debut in relief of Peterman. Few regard Allen as ready to play now, but the Bills might not have any choice but to turn to him as the starter.

Dallas Cowboys: So perhaps Ezekiel Elliott’s suspension wasn’t all that was wrong with the Cowboys last season after all. Elliott is back. But tight end Jason Witten retired and the Cowboys chose to part ways with wide receiver Dez Bryant, and quarterback Dak Prescott couldn’t get the offense going Sunday at Carolina. The Cowboys didn’t score until the fourth quarter. When they had a late chance to tie the game with a touchdown and two-point conversion, Prescott lost a fumble, and the Cowboys lost, 16-8. They couldn’t get their running game moving. Their offensive line struggled. They don’t have a wide receiver that scares a defense. This offense simply might not be good enough to get the Cowboys back into playoff contention.

Tennessee Titans: The loss at Miami in the weather-delayed marathon was bad enough. But losing quarterback Marcus Mariota, left tackle Taylor Lewan and tight end Delanie Walker to injuries was calamitous for the Titans, who are coming off a playoff season but nevertheless have a first-year head coach in Mike Vrabel. Mariota threw two interceptions and exited the game with an ailing right arm. Lewan suffered a concussion on a blind-side hit on an interception return. Walker was taken from the field on a cart with an injury to his right leg that could end his season. The AFC South is no joke these days, and the Titans can’t afford to fall too far behind.

Carolina Panthers: Yes, the Panthers beat the Cowboys. And yes, quarterback Cam Newton made certain that the offense did enough to win. But tight end Greg Olsen left the game in the first half and spent the second half on crutches on the sideline with his right foot in a boot. That’s the foot that Olsen broke last season. The Carolina offense simply isn’t the same without Olsen, a game-changing player who creates matchup nightmares for a defense. It’s doubtful that the Panthers can keep pace with the NFC’s heavyweights without Olsen being healthy and productive.

Arizona Cardinals: Has it ever been a good idea for a team to entrust its fortunes to quarterback Sam Bradford? Very little went well in Sunday’s defeat at home to the Washington Redskins. If this continues, it won’t be long before the season is reduced to a countdown to when the team turns to rookie Josh Rosen and begins looking to the future.

Oakland Raiders: An NFL team rarely has a worse day without actually playing a game. The Raiders don’t open the season until their Monday night meeting with the Los Angeles Rams. But their decision to trade Mack to the Bears, which looked unwise at the time the deal was made, looked even worse by the time Mack was done overwhelming the Green Bay offense in the first half Sunday night. It was a defensive performance as dominant as they come, at least for a half. Those two first-round draft choices that the Raiders landed in the Mack trade could come in handy in the future. In the meantime, Mack is doing all that he can to underscore what the Raiders will be missing from this season’s defense.

Green Bay Packers: Rodgers was tremendous Sunday night, returning to the field in the second half after exiting in a cart following a first-half knee injury. He threw three fourth-quarter touchdown passes as the Packers overcame a 20-0 second-half deficit to beat the Bears, 24-23. Rodgers vowed afterward to play this coming weekend against the Minnesota Vikings. But his knee clearly wasn’t completely sound Sunday night, prompting some observers to maintain that it was too risky for the Packers to put him back on the field in the second half against Mack and the hard-charging Chicago defense. That proved unfounded, as the Packers adjusted their offensive approach and Rodgers got the football out of his hand quickly. But it all underscored just how indispensable Rodgers is to the Packers. They simply aren’t very good without him. And if his knee is not right, another season could unravel rapidly.

Teams that can R-E-L-A-X a bit longer …

New Orleans Saints: The Saints thrived last season because of their balance. They ran the ball well. They played good defense. They didn’t have to rely solely on the passing of quarterback Drew Brees. All of that seemed like a distant memory Sunday. Brees threw for 439 yards and three touchdowns. But the Saints didn’t run the ball. They didn’t play sound defense. And they were overrun by the Tampa Bay Buccaneers, 48-40. For now, it can be considered an aberration. The Saints still have the players on the roster to replicate last season’s versatility. But they need to get back to that formula quickly.

Pittsburgh Steelers: It seems ominous now, with Steelers players venting their frustration about Bell’s decision not to report to the team last week. The performance Sunday in Cleveland was far from what a team with Super Bowl aspirations would expect. But Bell will show up eventually. He and his teammates probably will put their differences aside and move forward. Quarterback Ben Roethlisberger will play far better than he did in his turnover-laden outing against the Browns. The Steelers know how to endure a rough moment or two on their way to a successful season.

Los Angeles Chargers: They were the trendy pick to win the AFC West, so Sunday’s loss at home to the Kansas City Chiefs qualifies as a significant disappointment. The foot injury that kept pass-rushing standout Joey Bosa out of the lineup for the opener is worrisome. But the Chargers rebounded from a terrible start last season to contend. They’d simply better be careful not to allow the early-season hole that they dig for themselves this time to be too deep.

New York Giants: The Giants gave Eli Manning a chance for some success late in his career by drafting running back Saquon Barkley second overall rather than taking a quarterback to replace Manning, then making wide receiver Odell Beckham Jr. presumably content with a lucrative contract extension. Now it’s up to Manning to produce. The results were mixed in Sunday’s season-opening defeat at home to the Jacksonville Jaguars. Barkley’s long touchdown run reinforced that he’s the real deal. Beckham was productive. The defense showed signs of improvement. But Manning wasn’t great and the offensive line had its issues. For now, it can be attributed to facing an overpowering Jacksonville defense. Manning deserves the benefit of the doubt. But much depends on there being some good football left in him, and he needs to get things going in the coming weeks.

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