Messages of support for Thomas Hitzlsperger on Wednesday spread across Europe after the former Aston Villa player's decision to come out, although there were also warnings that the fight against homophobia in the game is still in its infancy.

Hitzlsperger, who follows the American Robbie Rogers as the most notable footballer in recent times to reveal that he is gay, received support from within his homeland Germany and throughout Britain.

However, the former NBA star John Amaechi, who came out after his retirement in 2007, believes that while Hitzlsperger's announcement should be welcomed it will change little within the spheres of influence in the English game who turn a blind eye to homophobia.

He said: "It's good to have more positive role models. He [Hitzlsperger] was a well respected player and adds to the pool of quality individuals who can set an example. But does anybody really think that the important people who really count in football – who are the members of the FA board, the executives there, the executives at the Premier League – does anyone really think there will be celebrations and revelation going on in those offices? Do you think people are really going: 'I get it now, Thomas has come out and I get it now'.

"But coming out to the world is a good thing. The mass majority of reaction is really positive but there are still some people who can't resist insults. It shouldn't be a big deal but it still is, and it still is because the environment of football is still toxic. Nothing changes until someone powerful within football decides to change it.

"A lot of people have sent me messages on Twitter and said 'it's not a big deal'. I know what they're saying because it's not a revolutionary thing that is going to change the earth. But it is important that we get new role models, when people step up and be authentic, when it is shown that gay people aren't just found in certain discreet industries."

Bayern Munich, the club where Hitzlsperger began his career, described his decision as a "brave step", while the Arsenal and Germany forward Lukas Podolski tweeted: "Respect to Thomas Hitzlsperger! That was a courageous and correct decision and an important step."

The reaction across Germany was similarly positive, despite claims in 2011 from the current Germany captain, Philipp Lahm, that he would not encourage a gay professional footballer to come out because of the pressures that could ensue.

The Bundesliga president, Reinhard Rauball, said: "The decision of Thomas Hitzlsperger to be the first prominent footballer to make public his homosexuality is – even after his active career – a huge and courageous step, and surely leads the way in the fight against homophobia."

A German government spokesman, Steffen Seibert, welcomed Hitzlsperger's announcement on behalf of the chancellor, Angela Merkel.

He said: "We live in a country where nobody should be afraid of acknowledging their sexuality for fear of intolerance. And I think that as a country, as a society, we've made enormous progress in this area. We judge footballers by whether they conduct themselves well and with dignity on and off the pitch, and I believe both are true for Mr Hitzlsperger."

The prime minister, David Cameron, tweeted: "As an #AVFC fan, I've always admired what Thomas Hitzlsperger did on the pitch – but I admire him even more today. A brave & important move."

The Gay Football Supporters' Network said: "It shows that we are moving one step closer to creating that atmosphere in football where players at all levels would be able to come out should they want to, safely and free from discrimination. We hope that one day current players would feel able to come out and that eventually a player's sexual orientation not be a news story, but for now we wish Thomas Hitzlsperger well."