If we’re being honest, and don’t live in Missouri or Kansas, it was hard buying into the Kansas City Chiefs as the clear Super Bowl favorite, even as they started 5-0.

Sunday’s game is why.

The Chiefs are a good offensive team but there was reason to be skeptical. There were too many conservative game plans and disappointing days in the Andy Reid/Alex Smith era to fully buy in. The Chiefs had 6 yards and one first down at halftime against the Pittsburgh Steelers. By the time they got it going in the second half, it was too late. Antonio Brown’s crazy deflected touchdown catch in the fourth quarter ensured the 1972 Miami Dolphins could sleep well tonight. The Chiefs were the NFL’s last unbeaten team, but they aren’t unbeaten anymore. The Steelers won 19-13.

Losing to the Steelers isn’t a crime, no matter how bad Pittsburgh looked last week. But this one was ugly for the Chiefs. The Steelers aren’t a great defense, but they looked like it for most of Sunday’s game. Smith, who had been off to a great start this season, had his worst game of the year. It looked better with a big fourth quarter, including a 57-yard touchdown pass to De’Anthony Thomas when the Steelers defense fell asleep. But the Smith we saw play so well the first five weeks never showed up. The Chiefs are often accused of not being dynamic enough on offense to win big, and Sunday’s loss won’t help change that narrative.

There were reasons for the off day. Tight end Travis Kelce wasn’t 100 percent all week in practice and had a quiet day. Receiver Chris Conley is done for the season with an Achilles injury. They faced a Steelers team that wanted to rebound from last week’s debacle against Jacksonville. Nobody expected the Chiefs to go undefeated this season anyway.

And it could have gone differently. Reid made the decision to go for it on fourth down near the end zone when the Chiefs trailed 12-3 in the fourth quarter, and they didn’t get it. The decision to pass on the field goal there will be second-guessed. And the Chiefs had a shot at the end. They got the ball back at their own 44-yard line after a nice punt return by Tyreek Hill with less than two minutes left. Smith could have erased everything bad that happened with one great drive, but he couldn’t do it. James Harrison had a big sack on third down and then Smith threw incomplete on fourth down.

The problem is we haven’t seen the Chiefs raise their game in the postseason. The Steelers are a team the Chiefs could face in January, and Kansas City’s offense was dominated most of the day. It was just one game. It doesn’t erase how good the Chiefs looked in a 5-0 start. It doesn’t mean their offense, which was averaging more than 400 yards a game before Sunday, isn’t one of the NFL’s best. They’ll be fine.

But if there’s some reticence over buying into the Chiefs as a Super Bowl favorite, it was because of performances like Sunday. That will stick with them until they prove otherwise in the playoffs.

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Frank Schwab is the editor of Shutdown Corner on Yahoo Sports. Have a tip? Email him at shutdown.corner@yahoo.com or follow him on Twitter!
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