Updated

Kansas City Chiefs quarterback Patrick Mahomes went off on the sidelines during the team’s close loss to the Buffalo Bills on Sunday night.

After Mahomes threw an incomplete pass to turn the ball over on downs, Mahomes went back to the sidelines and appeared to be giving NFL officials an earful. He then slammed his helmet down on the ground and had to be held back by coaches and teammates.

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Patrick Mahomes launches the ball

Patrick Mahomes of the Kansas City Chiefs throws during the second half of the game against the Buffalo Bills at GEHA Field at Arrowhead Stadium on December 10, 2023, in Kansas City, Missouri. (David Eulitt/Getty Images)

"We played our f---ing a--es off. That’s f---ing terrible, man," he was seen saying on the sidelines as the clock hit triple zeroes.

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The chaotic scene came a few plays after a touchdown was wiped off the board.

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Mahomes threw a dart to Travis Kelce who ran up the field and found Kadarius Toney trailing behind him. Kelce threw the ball behind himself to Toney, who had an open lane to the end zone.

However, the touchdown was taken off the board because Toney was declared offside. It appeared Toney lined up in the neutral zone as the play started. That’s against the rules and a penalty was called on Toney.

Patrick Mahomes and Josh Allen

Buffalo Bills quarterback Josh Allen, left, and Kansas City Chiefs quarterback Patrick Mahomes shake hands after their game, Dec. 10, 2023, in Kansas City, Missouri. (AP Photo/Ed Zurga)

The reversal seemed to suck the air out of Arrowhead Stadium as Kansas City couldn’t get anything else going. Mahomes was sacked on the next play.

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Bills linebacker Von Miller also appeared to be offside on one of the final plays.

Kansas City lost the game, 20-17, and fell to 8-5 on the season.

Mahomes finished 25 of 43 with 271 passing yards, a touchdown pass and an interception. Kelce led the way with six catches for 83 yards. Rashee Rice had seven catches for 72 yards, including a touchdown. Rice had a key catch that helped the Chiefs get down the field.

Josh Allen helped the Bills set up the Tyler Bass go-ahead field goal. He was 23 of 42 for 233 passing yards and a touchdown. James Cook had the touchdown catch.

Patrick Mahomes and the Chiefs

Patrick Mahomes #15 of the Kansas City Chiefs calls a play in the huddle during the second half of the game against the Buffalo Bills at GEHA Field at Arrowhead Stadium on December 10, 2023, in Kansas City, Missouri. (Jamie Squire/Getty Images)

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The Bills moved to 7-6 on the season and improved their playoff hopes.

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