Major League Baseball gave Pittsburgh Pirates pitcher Dennis Santana a four-game suspension on Friday for "his aggressive conduct toward a fan" that saw him take a swing at someone heckling him from behind the bullpen.

Santana's suspension was set to begin Friday, but the pitcher has elected to appeal the discipline.

Santana's run-in with the fan took place during the second game of a doubleheader at the Detroit Tigers on Thursday. A Tigers spokesperson confirmed to news outlets that the fan was ejected from the park.

Video of the incident posted to social media showed Santana leave his feet and take a swing at the fan who was standing over the railing. A Pirates coach ran in to guide Santana away from the stands.

Speaking via an interpreter after the game, Santana explained that the fan "crossed the line too many times" but that it didn't justify his own actions. He declined to say what the fan did or said to him.

"You guys know me and know my temper," Santana said. "I'm a calm person. They just crossed the line a few times. I would like to leave it like that."

Santana later entered that game and faced one batter before a rain delay interrupted the game.

Santana, 29, is in his first full season with Pittsburgh after the Pirates selected him off waivers from the New York Yankees in June 2024. In parts of eight MLB seasons for five clubs, Santana is 13-16 with nine saves and a 4.38 ERA across 237 appearances (one start).