PITTSBURGH -- By missing training camp, Le'Veon Bell was not present for the league officiating seminar that explained the new celebration rules.

And it cost the Pittsburgh Steelers running back 15 yards Sunday in Kansas City, where he used the goalpost pad as a punching bag after a 3-yard score.

Only the football can be a prop.

“I guess I wasn’t fully aware of that. Now I am," Bell said. "So I just won’t use the goalpost next time. Maybe I’ll use the JuJu [dance]."

The Steelers will take a 15-yard loss when Bell is putting up 191 of his own, earning AFC Offensive Player of the Week honors. But Bell said he was told on the sideline after the touchdown that only the football can be a prop. Then, he remembered Jimmy Graham used to get flagged for dunking on the goal post and "put two and two together."

“That was just kind of a spur of the moment right [thing] there," Bell said of the celebration. "I did plan something [else], but I had forgotten once I scored. But I had seen the goalpost and I had been doing a lot of boxing, so I just kind of boxed the goalpost. That’s the first thing that came in my head."

Le'Veon Bell is showing off his actual boxing skills. (via @L_Bell26) pic.twitter.com/lDxiUV6REA

— SportsCenter (@SportsCenter) October 17, 2017

The Steelers' defense didn't allow a score on the following drive, to the relief of Bell, who's preparing for the Cincinnati Bengals.

Linebacker Vontaze Burfict injured Bell's knee with a sideline hit in 2015, and Bell said Wednesday that it wasn't just Burfict who was targeting him that year.

"I expect them to go out there and play hard. It’s going to be what it is," Bell said. "He’s a great football player. I’m going to go out there and treat him with respect. ... I'll go out there and protect myself at all times."