SAN FRANCISCO - Baseball history will be made on a field of wistful dreams in Northern California's wine country Thursday with the appearance of the sport's first openly gay active professional.

Pitcher Sean Conroy, 23, is scheduled to take the mound in his first start for the Sonoma Stompers, a 22-man team that is part of the independent Pacific Association of Baseball Clubs.

The Stompers recruited the upstate New York native out of college in May. General Manager Theo Fightmaster says Conroy privately shared his sexual orientation with teammates and management before agreeing to come out publicly in time for the team's home field gay pride night.

''The first conversation I had with Sean was, `I want you to know this organization supports you, we respect who you are. We respect who you as a pitcher and a person and to whatever degree you want your story told, we'll help facilitate that,'' Fightmaster said. ''His goal has always been to be the first openly gay baseball player, so he was very much in favor of telling the story, of carrying that torch.''

Major League Baseball historian John Thorn confirmed that Conroy is the first active professional to come out as gay. Glenn Burke, an outfielder for the A's and Dodgers, and Billy Bean, a utility player with the Tigers, Dodgers and Padres, came out after they retired.

Conroy, a right-hander who has earned four saves and allowed only two hits in the seven innings he has pitched so far as a closer for the 15-3 Stompers, said he had been open with his high school, summer league and college teams and told his family he was gay at age 16. It would have been strange not to do the same once he moved across the country and started making friends on the team in Sonoma, he said.

Conroy's history-making start comes at a watershed moment for gay rights, with the U.S. Supreme Court scheduled to rule any day now on whether to make same-sex marriage legal across the nation.

The Stompers are not planning to make a special announcement or call attention to the milestone so Conroy can focus on his pitching, although some players will be wearing rainbow socks or other gay pride symbols in support of their teammate, Fightmaster said.

''As a small independent team we do try to find ways to be relevant, and this is certainly in that category. But I think the Giants would do the exact same thing if they were in this situation,'' he said. ''We try to saddle that line between respecting the game and doing what's right by the players who are here every day and doing stuff outside the box enough so people realize we exist.''