In texts to the AP, Wizards guard Garrett Temple wrote, "I was surprised. I didn't know and I was right next to him in the locker room. It definitely took a lot of courage for him to come out. He was a great teammate," and rookie Bradley Beal said: "I didn't know about it! I don't think anyone did! I am proud of his decision to come out and express the way he feels and I'm supportive of that!!"
Former teammate Jerry Stackhouse, now with the Brooklyn Nets, wrote in a text: "I hope Jason is received well by our NBA family. Jason is a friend and a former teammate that I've enjoyed many laughs and conversations with and his sexual orientation won't change that with me. I've already reached out to him personally to show support and will encourage more guys to do the same."
NBA Commissioner David Stern said in a statement: "Jason has been a widely respected player and teammate throughout his career and we are proud he has assumed the leadership mantle on this very important issue."
While Collins is the first male athlete in a major North American professional league to come out while intending to keep playing, several have previously spoken after they retired about being gay, including the NBA's John Amaechi, the NFL's Esera Tuaolo and Major League Baseball's Billy Bean.
"I think he is immensely brave. I think it's a shame in this day and age he has to be immensely brave, but he is," Amaechi told the AP. "He's going to be a remarkable and eloquent spokesperson for what it is to be a decent, authentic human being — never mind just for gay people."
Rick Welts, president and chief operating officer of the NBA's Golden State Warriors, is openly gay.
"He probably knows what he signed up for. There'll be a whole bunch more television reporters and cameras than he's probably had in the past. ... There had been a long of speculation about when, who, how. I think that speculation has been put to rest now," Welts said, "and we'll always remember that Jason Collins was the first man to do this."
Collins says that if he remains in the NBA, he could face uncomfortable reactions from spectators.
"I don't mind if they heckle me. I've been booed before. There have been times when I've wanted to boo myself. But a lot of ill feelings can be cured by winning," he writes.
He adds: "I hope fans will respect me for raising my hand. And I hope teammates will remember that I've never been an in-your-face kind of guy. All you need to know is that I'm single. I see no need to delve into specifics."
In February, former U.S. soccer national team player Robbie Rogers said he was gay — and retired at the same time. Rogers is just 25, and others have urged him to resume his career.
"I feel a movement coming," he tweeted after word of Collins' news broke.
Female athletes have found more acceptance in coming out; Brittney Griner, a two-time AP women's college basketball player of the year now headed to the WNBA, caused few ripples when she said this month she is a lesbian. Tennis great Martina Navratilova, who came out decades ago, tweeted Monday that Collins is "a brave man."
"1981 was the year for me — 2013 is the year for you," her post added.
Sports leagues in Britain and elsewhere in Europe have been trying to combat anti-gay bias. But the taboo remains particularly strong in soccer, where there are no openly gay players in Europe's top leagues. Homophobic chants are still heard at some games.
Soccer "is not going to change," said Amaechi, who is English and now lives in Manchester. "If it wanted to change, it would change. It has the resources to do so. It doesn't want to change."
Justin Fashanu is the only significant British soccer player to have come out publicly, doing so in 1990. The former Nottingham Forest and Norwich City striker was found hanged in a London garage in 1998 at age 37. According to an inquest, Fashanu left a note saying that, because he was gay, he feared he wouldn't get a fair trial in the United States on sexual assault charges. Maryland police were seeking him on charges that he sexually assaulted a 17-year-old boy.
Among other athletes outside the U.S. to come out was Gareth Thomas, a Welsh rugby star who attracted widespread media attention in 2009 when he announced he was gay. He continued playing until retirement in 2011.
Orlando Cruz of Puerto Rico came out in October as the first openly gay professional male boxer. Canadian swimmer Mark Tewksbury came out six years after winning a gold medal in the backstroke at the 1992 Barcelona Games. Four-time Olympic diving gold medalist Greg Louganis of the U.S. revealed he was gay in 1994, a year before announcing he was also HIV-positive. Former Olympic skiing gold medalist Anja Paerson of Sweden announced last year, after retiring, that she was in a long-term relationship with a woman.
In SI, Collins recounts that the first relative he came out to was his aunt, Teri Jackson, a San Francisco Superior Court Judge.
"I don't think Jason looked at his life as being a trailblazer," Jackson said Monday.
"He has no regrets coming out," she added. "And he wants to play. And we'll see what happens next."
White House spokesman Jay Carney called Collins' decision courageous and said the administration views it as another example of progress and evolution in the U.S. as Americans grow more accepting of gay rights and same-sex marriage.
Former President Clinton said: "Jason's announcement today is an important moment for professional sports and in the history of the LGBT community. It is also the straightforward statement of a good man who wants no more than what so many of us seek: to be able to be who we are; to do our work; to build families and to contribute to our communities. For so many members of the LGBT community, these simple goals remain elusive."
Collins attended Stanford with Clinton's daughter Chelsea and played in a Final Four while at the school. His twin brother, Jarron, was also a longtime NBA center who last played in the league in the 2010-11 season. Collins says he told his brother he was gay last summer.
"He was downright astounded. He never suspected. So much for twin telepathy," Collins writes in SI. "But by dinner that night, he was full of brotherly love. For the first time in our lives, he wanted to step in and protect me."
Advocacy organization GLAAD released a statement from Aaron McQuade, the head of its sports program.
"Courage' and 'inspiration' are words that get thrown around a lot in sports, but Jason Collins has given both ideas a brand new context," he said. "We hope that his future team will welcome him, and that fans of the NBA and sports in general will applaud him. We know that the NBA will proudly support him, and that countless young LGBT athletes now have a new hero."
As a senior at Stanford, Collins was a college roommate for about six months with then-sophomore Joe Kennedy III, who now represents Massachusetts in Congress. In his account, Collins writes that he realized he needed to go public when the Democratic congressman walked in Boston's gay pride parade last year — and Collins decided he couldn't join him.
"I didn't doubt for a second, knowing he was gay, that he would be the one to do it," Kennedy told the AP on Monday. "I've never known him to look for publicity, or to look for the spotlight, but given that no one else would raise their hand, I knew he would do it."
Added Kennedy: "I'm so proud of him. And I'm so proud to call him a friend."
In Monday's story, Collins writes that the Boston Marathon bombing on April 15 "reinforced the notion that I shouldn't wait for the circumstances of my coming out to be perfect. Things can change in an instant, so why not live truthfully?"
And now, Collins and Kennedy say, they will be in Boston on June 8, marching together at the city's 2013 gay pride parade.
"Some people insist they've never met a gay person. But Three Degrees of Jason Collins dictates that no NBA player can claim that anymore. Pro basketball is a family. And pretty much every family I know has a brother, sister or cousin who's gay," Collins concludes. "In the brotherhood of the NBA, I just happen to be the one who's out."
AP Sports Writers Joseph White, Nancy Armour, Larry Lage, Brian Mahoney, Antonio Gonzalez, Rachel Cohen, Paul Newberry, Jimmy Golen, Howard Ulman, Rob Harris, Steve Wilson, Richard Rosenblatt and Tom Withers, and Associated Press Writers Mary Clare Jalonick, Cara Rubinsky, Jennifer Agiesta, Steve Peoples, Josh Lederman and Terry Chea contributed to this report.
Howard Fendrich is on Twitter at http://twitter.com/HowardFendrich