Since September, advocates for same-sex marriage in New York have released 30-second videos of celebrities endorsing their cause. More than 30 have taken part, including the actors Julianne Moore and Sam Waterston, Mayor Michael R. Bloomberg and the former first daughter Barbara Bush. On Thursday, former President Bill Clinton released a written statement of support, too.

Until now, supporters have come mostly from the worlds of politics, entertainment, theater and fashion. One type of New York celebrity was conspicuously absent: the athlete.

Enter Rangers forward Sean Avery.

He recently recorded a video, becoming one of only a few active athletes in American team sports to voice support for gay rights, and is believed to be the first in New York to publicly advocate for same-sex marriage. No active male player in a major American team sport has declared his homosexuality, and homosexual slurs remain in use to insult opponents and officials.

Avery, a 31-year-old from Pickering, Ontario, has played nine seasons in the N.H.L. Known as a fashion-conscious, on-ice agitator, he has never been afraid of what others think of him.