Anton Hysén looks every inch the modern footballer. The 20-year-old Swede has his initials tattooed behind one ear and his parents' names on each forearm. On his left arm, in particularly elaborate lettering, is: "UNWA". This is Hysén's tribute to Liverpool, his birthplace, and the terrace anthem of his favourite club – You'll Never Walk Alone.

Hysén, the son of former Liverpool defender and Swedish international Glenn Hysén, is currently walking very much alone. This month, the left-sided midfielder came out as Sweden's first openly gay male footballer. He is only the second high-level footballer to come out in the world, ever. The first, Justin Fashanu, revealed he was gay in 1990, found himself shunned by the footballing world, including his brother, John, and hanged himself eight years later. (John later expressed his remorse.)

A generation on, when gay men and women play prominent roles in every other kind of entertainment, it looks increasingly bizarre that world football has no openly gay players – apart from Hysén. Although, as he points out, he currently plays in the fourth tier of Swedish football, working in the local Volvo factory to support himself, Hysén's honesty about his sexuality is a big deal. His family is a footballing dynasty in Sweden; Hysén's older brother, Tobias, is a Swedish international; their father, Glenn, was a tough defender who remains a celebrity in Sweden. In Britain, it would be rather like John Terry having a footballing son who came out. Perhaps most significantly of all, Hysén, like the English cricketer Steven Davies, who came out last month, made his declaration at the start of his career.

A bouncy, articulate athlete who speaks excellent English with an American twang picked up during a year at college there, Hysén is utterly at ease with his decision when we meet at his family's apartment in Gothenburg before his team, Utsiktens BK, play their first big match of the new Swedish season. He has no time for gay stereotypes. As he politely puts it: "I'm not a big Pride person. There's nothing wrong with Pride but it's just not my thing."

His story began, however, at Stockholm's Pride march in 2007, when his dad made a surprising appearance. It was controversial because the gay community assumed Glenn was a homophobe after he threw a punch at a man who groped him in the toilets at Frankfurt airport in 2001. But this macho football legend confounded critics by talking with great empathy of "a 16-year-old who didn't want to come out because he feared what his teammates would think". No one realised at the time, but he was referring to his son. "He said, 'I'm doing it for you,'" remembers Hysén.

Hysén's family and close friends have been completely supportive since he revealed his sexuality to them a few years ago; he figures he was born this way. "I always knew but I didn't really think about it seriously when I was younger – you live at home and hang out with girls and you only really think about it when you start to want a serious relationship," he says. Injuries stalled his development as a footballer with the Swedish premier-league club Häcken and now Hysén is rebuilding his career at Utsiktens, where his father became coach last year. Hysén did not court the flurry of global publicity that, invariably, came with his revelation. During a football magazine interview, Glenn casually mentioned his son's sexuality; the journalist then politely approached Hysén to see if he wanted to come out. Hysén thought he might as well and, with typical frankness, told Offside magazine: "It is completely strange, isn't it? It's all fucked up. Where the hell are all the others? No one is coming out."

That is probably because homophobia is rife in global football, from the top to the bottom. When Fifa last year awarded the 2022 World Cup to Qatar, where homosexuality is illegal, president Sepp Blatter sniggered that gay fans "should refrain from any sexual activities" if travelling there. "Thank goodness only healthy people play football," said Vlato Markovic recently, vowing there would be no gay players while he was president of Croatian football. In 2009, Max Clifford claimed he advised two gay Premiership players to stay in the closet because football was "in the dark ages, steeped in homophobia". Last year, Gordon Taylor, head of the Professional Footballers' Association, casually remarked that homophobia was not high on the Premiership's agenda after no footballers would front the FA's anti-homophobia video campaign.

Calling football "institutionally homophobic", as Ben Summerskill of Stonewall put it, looks like an understatement. A Stonewall survey found seven in 10 fans have witnessed homophobic abuse. In 2009, seven men were found guilty of hurling taunts at Sol Campbell, in the first case of indecent chanting brought to court. Ipswich supporters still repeat: "He's gay, he's dead, he's hanging in a shed, Fashanu, Fashanu" at fans of Norwich, where Fashanu began his career.

Even if this is excused as pantomime tribal rivalry, the violence of it is terrifying. But Hysén does not fear his experience will in any way replicate Fashanu's. "His teammates and his brother turned their backs on him," he says. "That's the biggest tragedy." Hysén's glamorous, fur coat-wearing mother, Helena, vividly recalls Fashanu's coming out shaking footballing circles when she was living on Merseyside with Glenn and their children. "I remember this picture when he was lying down on the grass under an oak tree just in jeans and he told the world he was gay. Everyone was like: 'What the heck is he doing?'" She hopes it would be different now in Britain, although, as she puts it: "English men are more conservative [than Sweden]. They still wear wigs in court."

Two hours before Utsiktens kick off against Assyriska in the regional cup final, I grab a lift with Hysén and his dad to their stadium. So far, reaction has been the polar opposite to that surrounding Fashanu, except for one offensive letter from a fan. "Everyone has been very positive. I was on the train last weekend and this girl said: 'You've made the world a better place, thank you for being there for everyone,' and I haven't done anything," Hysén smiles. "But when you think about it, you kinda have. Obviously I haven't been playing in the top league but I'm still going for it, and I'm still the only active player who has come out, so of course it's huge."

Fans might assume it is impossible for footballers to come out because of teammates – or managers. Brian Clough treated Fashanu brusquely after his million-pound transfer to Nottingham Forest in 1981 and the striker's career fell into terminal decline. Hysén has two managers at Utsiktens; his dad is strongly supportive and his other coach, recounts Hysén, told him: "I support you 100%. If anybody else says anything we'll kick them out. Just do your thing." Hysén understands other gay players might fear discrimination by managers because of their sexuality but "if someone turns you down because of that, they would be the dumb one".

Dressing room "banter" is notoriously Neanderthal but Hysén insists he is totally comfortable at Utsiktens. "Everyone is positive. Everyone," he says of his teammates. It may help that nine of the team are under 22. "Who cares about a gay joke? I do it too. I joke about myself." Before the cup final, the Utsiktens players slouch around in flipflops and tracksuits, playing computer games and cards. The smell of Deep Heat rises from the dressing room; Guns N' Roses pumps from the stereo. "We're an international team," explains Sonny Karlsson, a big Serb-Swedish striker, pointing out teammates from Bosnia, Germany and Albania. "And we've got a fag, how about that?" adds Hysén.

Rightwinger Niklas Tidstrand, a friend for five years, has publicly supported Hysén. "We're a really good, tight group – perhaps that's why Anton came out as well," says Tidstrand of their young squad. "It's good for him. He doesn't have to lie when girls come up to him. It's hard to have something inside you that's really big. I supported him from the first moment he said he was gay and when he came out to everybody I thought it was good but we didn't think it was going to be a big deal like this."

Premiership players are startlingly reluctant to talk about homophobia or gay players in the game, as if they will be marked men simply for discussing the issue. Former Sheffield Wednesday captain Darren Purse said he would have to think hard before advising a young player to come out; Bayern Munich's German striker Mario Gomez made headlines when he did the opposite, urging gay players to break this last "taboo". Hysén hopes his brother Tobias's support might encourage other top Swedish footballers to come out. "Other players should know he is someone they could talk to as well," he says. Hysén would like to see Premiership players stick up for gay colleagues. "If you're a real man in the Premier League you'd say, 'If you've got a problem, call me.' There has to be some way – whoever plays in the Premier League should try to support them."

Does Hysen feel pressure to be a role model now he is football's only gay player? "Not at all," he says. "There's nothing to be a role model for – you're gay, it's not a big thing. People tell me I'm a celebrity now, and I shouldn't be. But as long as it helps [others by speaking openly], I'll do everything I can. If there's anyone afraid of coming out they should give me a call."

Hysén admits it made it easier to come out given the fact that Utsiktens count their crowds in hundreds rather than thousands. Last week's cup final was the biggest game Hysén had played since he came out.

At half-time, Utsiktens fans of all ages are supportive of Hysén, although there are a few old jokes. "What we say is, 'Don't drop the soap in the shower, boys,'" says one fan. "He has really placed our team on the map. Everybody knows what is Utsiktens – it's Anton Hysén," beams Thelma Lingonblad, an elderly stalwart. "It's very brave coming out like that," nods Lars Borjessön. "The media minds more than us," declares young fan Selma Arnautovic, just as Utsiktens grab a second goal. "Lots of people think it's his private life. People don't think any differently about him. They like the way he plays," she smiles, "not which side he is on."

Hysen is not dating anyone and says he would "just laugh" if future romances were reported in the press. The media "can say whatever they want as long as it's not bullshit". He is finding it "really hard to find someone within sports that acts like you" – "masculine", as he puts it. "I like to go to gay bars but it gets a little bit too much when it comes to Pride. We'll see. You meet people every day so no stress. I'm not searching for anything."

It may be easier to come out in Sweden, that bastion of liberal civility. Hysén is a great Anglophile (even sporting the St George's flag on his personalised boots) but agrees that Sweden is more tolerant. "People here are a little bit more liberal but I understand people of other cultures and religions if they don't respect it," he says of his sexuality. "You can't love everyone."

And it is not all peace and love in Sweden. Hysén's mother is worried about his meeting bigger clubs. "Three or four teams in the highest league have really bad fans," she says. "If they meet a team like that, I don't think Anton gets scared. He gets more determined. But I'm scared. I'm his mum. And if he goes out to a nightclub, everyone knows him now. I'm scared he'll get beaten up."

As the match enters the final 10 minutes, Tidstrand is sent off for his second yellow card. Cursing on the sidelines, he says Assyriska's fans were shouting: "Are you sure you are just Anton's friend?" and "Are you gay as well?" at him. "It's the first time it's happened."

Utsiktens win the cup 2-1. Fans run on to the pitch, celebrating. "The left foot is back!" says Hysén delightedly. But, for the first time, he was abused. "I heard so much shit," he says of the opposition fans. "'Fucking faggot' and things like that." Hysén admits he was initially furious. Then "I was laughing, I was psyched to play the game. It's just talk. It's just shouting. My attitude is: 'I've got the ball – you don't. I'm on the pitch – you're not.' And if you hate that, I couldn't care less." He points out that he heard other fans telling his abusers: "Shut up, you can't say things like that."

Hysén heads home with his mum and sister, looking forward to a proposed trip to Britain for a televised discussion with gay sportsmen Steven Davies and Gareth Thomas and then to watch his beloved Liverpool. There with the rest of the fans he will belt out You'll Never Walk Alone. Perhaps he won't have to for much longer.