Homosexuality is seen as a major taboo in some sports, while not so much in others. Billie Jean King and Martina Navratilova, both openly gay, are two of the greatest tennis players in history. But big-time professional football, and the four major sports in the United States, are quite a different story — at least for now.
"(There is) a long way to go because we fear a reaction and we don't know what will happen. I can't imagine playing football and doing this at the same time," Hitzlsperger said in an interview with BBC Radio 4 on Thursday.
Hitzlsperger, no longer active but still regarded as the biggest name in football to say he is gay, spent years playing professionally in England, Germany and Italy. He also represented Germany at the 2006 World Cup.
His decision to go public was hailed overwhelmingly as a positive step in the German media as well as in England, reflecting the way attitudes have changed.
British tabloid The Sun labeled him a "Winner" in a side-by-side cover photo with Manchester United defender Chris Smalling, who was called the "Loser" for wearing an outfit resembling a suicide bomber for a costume party.
In Germany, Hitzlsperger has been commended for his courage. The country's mass circulation daily Bild led with "Respect!" on its front page, a day after Hitzlsperger made his announcement in an interview with German newspaper Die Zeit.
"Hopefully, by talking about it, it encourages some others, because they see they can still be professional football players, they can play at the highest level, and be gay," Hitzlsperger said in a video on his website. "It's not a contradiction, as I've proved."
Using anti-gay slurs and jokes on the sports field has been widely accepted as part of playing hard for years, so much so that in 1999 former Liverpool striker Robbie Fowler made lewd anti-gay gestures during a game toward Graeme Le Saux, who was playing for Chelsea. Le Saux, who is straight, was labeled a homosexual by many simply because he used to read the left-leaning Guardian newspaper.
On Thursday, in the wake of Hitzlsperger's announcement, Fowler took to Twitter to express regret and apologize for his actions of nearly 15 years ago.
"Getting a bit of stick for something that happened when I was a kid, naive and immature..I've apologised to @graemelesaux14, he accepted," wrote Fowler, who has retired from football and become a television commentator. "Obviously embarrassed looking back, but sadly cannot change what happened, you learn from mistakes growing up, and that I have."
Jason Collins, a former NBA player, came out last year and was regarded as the first active openly gay player in one of the big American sports. Like Hitzlsperger, Collins' announcement was met mainly with praise, rather than abuse.
Arjen Robben, the Dutchman who was a key player in leading the Netherlands to the World Cup final in 2010, downplayed stereotypes that athletes are scared to come out because they fear reprisals from teammates in the locker room.
"He's gay, and?" Robben said at a Bayern Munich practice session in Doha, Qatar. "I think it's quite normal and natural. I can also say here, I'm heterosexual. I don't see a problem."
FIFA, the governing body of football around the world, acknowledged that there is still work to be done within the game itself.
"Unfortunately, prejudices still exist within football," FIFA said in a statement. "FIFA is working hard to tackle these and hopes Thomas's statements will encourage greater respect and understanding in football and beyond."
Last February, American player Robbie Rogers declared he was gay as he announced his retirement. Rogers, now 26, has returned to action with the Los Angeles Galaxy. Former English player Justin Fashanu, who played for Norwich and Nottingham Forest, was the first football player to say openly that he was gay, in 1990. He committed suicide eight years later at age 37. Swedish defender Anton Hysen came out in 2011.
"I don't know if football is such a homophobic environment. People just speculate this would be the case," Hitzlsperger told the BBC. "Since we haven't seen a gay footballer in the Premier League or the Bundesliga, it's hard to say that this would happen. We would have to wait and see."