The Buffalo Bills made the flight to Miami coming off their best win of the season.
They flew home after their worst loss.
Most things that could go wrong against the Dolphins did for the Bills.
And just as much as they showed in beating the Chiefs in Week 9 that they can go on to win the Super Bowl, they showed in Week 10 that there's some brokenness on this Buffalo team that could stop them short of the ultimate goal, too.
These are four of the biggest problems to come out of Sunday's game:
Dalton Kincaid injury update
The Bills lost star tight end Dalton Kincaid during the second half.
Running a route, he pulled up lame and immediately grabbed at his right hamstring.
Kincaid was initially called questionable to return, then went to the locker room and was ruled out.
A nagging hamstring injury for the Bills' best pass-catching playmaker would not be good news for a Buffalo team that isn't getting it done in the passing game anyway.
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Why did the Bills not trade for a WR?
The Bills had a bunch of needs before last Tuesday's NFL trade deadline. They didn't fill any of them.
The largest one loomed Sunday at wide receiver, where yet again Buffalo's wideouts didn't create enough separation to make plays.
Keon Coleman did have one big play on a touchdown grab, but even there, he wasn't open. He just went up and snagged the ball.
Khalil Shakir remains useful out of the slot.
But too often, the Bills can't get things going in the passing game, even with an MVP at quarterback in Josh Allen.
The fact that they didn't remedy one of their biggest needs, instead letting Jakobi Meyers go to the Jags and Jaylen Waddle go nowhere, could matter greatly the rest of this season.
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Josh Allen turnovers
Allen isn't the turnover-prone QB that he was early in his career.
But with the Bills' pass catchers not making plays, Allen is doing everything he can to put the team on his back.
He threw an early interception in the end zone, which wasn't great.
And then on a powerful QB sneak that Allen just kept running on, he didn't give up, and he had the ball knocked loose while he tried to surge for a few extra yards.
Early this season, Allen protected the ball intensely.
Now, it looks just a bit like he's pressing.
The Bills need to figure things out around Allen so he can continue to be the best version of himself.
If Buffalo doesn't solve its other woes, Allen's Superman routine will have to be enough.
Where's the run defense?
This item wasn't even going to be on the list.
Then De'Von Achane ran for his second long touchdown of the game.
The Bills' run defense has been poor all season, and injuries haven't helped. Ed Oliver is out for at least the rest of the regular season with a torn biceps.
When Buffalo struggles, teams just run right through them.
That's exactly what Achane did on Sunday. It was far from the only reason the Bills lost.
But if the run defense isn't better, and the offense isn't better? There may be a few more ugly weeks ahead.
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