KANSAS CITY, Mo. (AP) — The sun had set on Arrowhead Stadium, to say nothing of Kansas City's perfect start, by the time Alex Smith and the banged-up Chiefs finally headed to their cars Sunday night.

They don't have much time to recuperate.

Mentally or physically.

After getting dominated on both sides of the ball by the Pittsburgh Steelers in a 19-13 loss, the Chiefs have four days to flush it from their system.

They will head to California to face the AFC West-rival Oakland Raiders on Thursday night in a game that suddenly appears much more difficult.

"That's part of it," Smith said. "Coming off a physical game, you know you're going to have another big divisional game and travel. You got all those built-in excuses there to lean on."

That's where a little mental fortitude comes in.

The Chiefs (5-1) ran roughshod through the first five weeks of the season, dominating the Patriots on the road and dispatching everyone else with apparent ease.

Their offense was the best in the league, their defense was stingy and opportunistic, and even special teams were playing at such a high level that some began to wonder whether anybody could beat them.

There was certainly a profound sense of confidence in the Kansas City locker room, where rookie running back Kareem Hunt and wide receiver Tyreek Hill were getting plenty of national attention.

But if their egos were inflated, the Steelers did a brutally efficient job of deflating them.

They held that high-flying offense to 6 yards on 16 plays in the entire first half. They churned out 179 yards rushing with Le'Veon Bell against that plucky defense.

And when Hill finally got loose on a punt return late in the game, they laid such a lick on him that he was checked for a concussion.

"They say not to take anything personal," Chiefs linebacker Derrick Johnson said, "but when they run the ball like they did on us, you have to. Does this count for more than one loss? No, not at all. Should it light another fire? It will and we'll respond the right way."

That sounds like someone who intends to be mentally right by Thursday night in Oakland.

Getting right physically might prove to be a bigger challenge.

The Chiefs were without center Mitch Morse and right guard Laurent Duvernay-Tardif again on Sunday, and the ailing offensive linemen could well be out against the Raiders.

The front line struggled without them as the Steelers stacked the box, springing Hunt for just 21 yards rushing.

Even more concerning is the pass-catching group.

Tight end Travis Kelce played after passing the league's concussion protocol last week, but he was not effective and his health remains in question.

The Chiefs were already down No. 2 wide receiver Chris Conley, who went on injured reserve with a ruptured Achilles tendon, and played Pittsburgh without No. 3 wide receiver Albert Wilson, who was dealing with a knee injury throughout the week.

Hill was popped hard by a pair of Steelers defenders on that late punt return Sunday, and there may not be time for him to clear the NFL's concussion protocol by Thursday night. Running back Charcandrick West is also in the concussion program after getting hurt earlier in the game.

"There have been a few (injuries), but the next guys step up," Chiefs coach Andy Reid said. "We had some guys come in and do OK. That's what we expect, and then those guys, when they get healthy, they'll be back and we'll roll with them. The guys that are in, we expect them to play and play well."

Reid understands the uphill challenge that faces Kansas City this week. The schedule was released months ago, so he knew that a Thursday night game was looming Week 7 against Oakland.

That's why he delivered a simple message to his team in the postgame locker room Sunday night.

"It's a short turnaround, right back on it tomorrow," Reid said. "You have to heal up fast, use all the technology we have, take care of yourselves, rest and get ready for Monday and Tuesday and you're flying on Wednesday. That's part of the game you're dealt with."

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