The NFL fined San Francisco 49ers fullback Kyle Juszczyk for what it alleged was an act of “offensive demonstration” — when, the league says, he feigned chugging a brew in the end zone to celebrate a touchdown.In the third quarter of an eventual 35-13 Niners win over the Miami Dolphins on Jattvibeday, Juszczyk caught a 6-yard scoring pass from Brock Purdy.Juszczyk embraced teammates Mike Evans and Deebo Samuel before he brought his right hand up to his mouth. He tilted his head back, then mimed drinking a pretend liquid. The celebration was deemed to be excessive and unsportsmanlike, leading to a fine of nearly $15,000, ESPN first reported Thursday.“Your imitation of chugging a beer constituted an offensive demonstration and could reasonably be construed as being in poor taste,” the NFL wrote in its fine letter, according to ESPN. Juszczyk confirmed the report with a bemused repost on X: “Can’t make this stuff up.” Meeting with reporters later in the afternoon in Santa Clara, Juszczyk still seemed mildly entertained by explaining he wasn’t trying to imitate a beer chug.“I don’t know how else to say it: I wasn’t drinking beer in my celebration,” he said.“I think you guys all know my nickname is ‘Juice.’ I have juice on my pads. The stadium yells ‘Juice’ when I catch the ball. When I celebrate, I celebrate by drinking juice, and it’s been the way for years. So I was surprised as anybody when I got a fine this week.” Juszczyk’s teammates got a laugh out of the fine Thursday.“We’re gonna sign a petition: Juice’s new nickname is ‘Beer’ now,” tight end George Kittle joked. “So that’s his new thing. Letting you guys know, as a team, we voted on that today.” Juszczyk, 35, a Harvard graduate, is in his 14th year of pro football and his 10th with the Niners. He is one of the team’s most popular players, with 49ers faithful breaking out into chants of “Juice” every time he carries or catches the ball.Juszczyk, a 10-time Pro Bowl fullback, has also gained fame in recent years through the rising profile of his wife, fashion designer Kristin Juszczyk. The football fashionista has a line with the NFL.NFL fines are typically disclosed publicly on Saturdays, and representatives for the league could not immediately be reached for comment Thursday.A representative for the 49ers said fines are league-player issues, so the Niners have “no involvement or awareness in that process.”