A 22-year-old man was stabbed on a J subway platform in Brooklyn Wednesday afternoon – possibly during a large fight, police sources said.

The man was stabbed on the northbound side of the J line at the Crescent Street Station in Cypress Hill around 4:20 p.m., authorities said. He was taken to Jamaica Hospital in serious condition.

Police sources said there was a large group of people on the platform and that there may have been a fight.