The Kansas City Chiefs Collapsed. But the Cracks Were Already Showing.

But for the right opponent, it was proof that the Chiefs might just be there for the taking. And on Sunday, the Philadelphia Eagles were the team that finally capitalized. 

When they routed the Chiefs 40-22 in Sunday’s Super Bowl, it both ended Kansas City’s bid for a three-peat and exposed deep-seated flaws in what had looked like an indomitable juggernaut. Even though the Chiefs had won back-to-back titles and posted the best record in the NFL again this year, the cracks had long been apparent to anyone who could get close. Philadelphia, in the end, was the team to bust them wide open.

“You don’t lose like that without everything going bad,” tight end Travis Kelce said.

With one blowout loss, the Chiefs suddenly face existential questions about how much needs to change for them to restore their dominance during the next phase of the Mahomes era. The offensive line allowed him to get sacked at the highest rate of his career. Kelce is 35 years old and coming off his worst full season as a pro. Many of the team’s other top skill-players were brought in as stopgap help. 

That means for the Chiefs to get back on top of the sport, they don’t merely need to show up and play better than they did when they got blanketed by Philadelphia’s defense. They’ll have to retool a roster that was able to paper over its shortcomings until they were exposed on the game’s biggest stage. 

“It was a rough day,” Chiefs head coach Andy Reid said. “We didn’t play well in any of the phases. I didn’t coach good enough.”

For much of the regular season, the Chiefs had clung to their stellar record by the skin of their teeth. Hidden in their 15-2 campaign were 12 victories in one-score games, many of which required them to pull a rabbit out of a hat. 

In football circles, winning so many nail-biters is often seen as a signal of luck, not great football. And Kansas City’s run was beginning to look like a hot streak at the roulette table. Dating back to last season, they had won a record 17 consecutive one-possession games. The chances of prevailing in all of them, based on their win probability entering the fourth quarter in each, was about 1-in-4,480, according to the NFL’s Next Gen Stats. 

Throughout it, the Chiefs ability to keep winning helped disguise that they were no longer an unstoppable force stacked with talent. During the early years of the Mahomes era, Kansas City was a big-play machine with speedster receiver Tyreek Hill and Kelce in his prime. From 2018 to 2021, Mahomes had more 25-yard pass plays than any other quarterback. 

But that began to change the following year. Despite leading the NFL in yards and points in 2022, they opted to trade Hill instead of giving him a big contract. Kelce’s play made up for it, though it couldn’t hide the fact that there were 21 receivers with at least 1,000 yards that season and none of them played for Kansas City. 

Once Kelce’s production started to wane, the team’s patchwork receiving corps only became more apparent. The once-vaunted Mahomes offense finished 15th in the NFL in points in each of the past two seasons. They brought in veterans such as Marquise Brown and DeAndre Hopkins to try to inject some life, but they did little to rekindle the team’s explosiveness. 

At the same time, the 29-year-old Mahomes started to come under duress more often. He was sacked a career-high 36 times this past year. He was also hit 70 times, another career high. All of which was easy to ignore as Kansas City won Super Bowls when Kelce found drips of gas in the tank during the postseason. 

And then, on Sunday, all of the team’s problems came home to roost against the Eagles. 

On a night when nearly everything went awry for the Chiefs, their most reliable plays seemed to desert them. Mahomes, who can often shift the momentum of a game with a single well-timed run, gained just 25 yards with his legs. His arm wasn’t much better as he completed just 6 of 14 passes for 33 yards in the first half.  

“I didn’t play to my standard,” Mahomes said. 

Even his favorite target seemed to vanish. Mahomes wasn’t able to connect with Kelce until the second half when the Chiefs were already in a 27-point hole. Two previous throws Kelce’s way had bounced off his fingertips.

And the offensive line simply crumbled. The Eagles didn’t send a single blitz on 42 dropbacks and still sacked Mahomes six times, more than anyone had ever managed against him in a playoff game. The last of them proved to be the most embarrassing as Mahomes went down under a tackle by Milton Williams and coughed up the ball on his 20-yard line.

“He’s a human being,” Chiefs wide receiver DeAndre Hopkins said, “and I guess the world got to see that.”

Now as the Chiefs head into the offseason, there are glimmers of hope. Rookie receiver Xavier Worthy, who set the NFL combine record in the 40-yard dash, has shown signs of bringing back that big-play quality to the team’s offense. And second-year wideout Rashee Rice, who missed most of the season due to injury, is expected to return. 

Still, rebuilding around Mahomes and his mega contract won’t be easy. His cost against the salary cap next year is set to skyrocket to over $66 million, pending any changes in his deal that punt those costs further down the road. 

The Chiefs aren’t strangers to retooling on the fly, though. The last time they were manhandled in this game, by the Tampa Bay Buccaneers, they revamped much of the roster around Mahomes and it led to two more Super Bowls. 

Now they have to do it again. 

Write to Andrew Beaton at andrew.beaton@wsj.com and Joshua Robinson at Joshua.Robinson@wsj.com