Patrick Mahomes engaged in a bit of friendly trash-talking over the summer but was forced to own up to it when Justin Herbert and the Los Angeles Chargers handed the Kansas City Chiefs their second loss of the season on Sunday. 

While playing at the American Celebrity Golf Championship in Lake Tahoe, California, in July, Mahomes was cautioned by a fan to "watch out for Justin Herbert next year." He responded, "I’ll see it when I believe it," seemingly mixing up the popular expression.

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After Herbert threw the game-winning touchdown with just 32 seconds left, Mahomes was certainly a believer. 

"I guess I believe it. That’s all you can say," Mahomes replied when a reporter asked about his comment. 

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Herbert finished with 281 yards passing and four TDs without an interception, outdueling Patrick Mahomes in a matchup of two teams expected to compete for a division title

"Nobody is happy with the way we played," Mahomes said after the game. "You take a loss to a division opponent, it's not a good thing. We haven't done a lot of that in my time here. It's how you respond. We have a long season ahead of us."

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Mahomes finished with 260 passing yards, three touchdowns and two interceptions in the Chiefs’ 30-24 loss.

The Associated Press contributed to this report.