The 27-year-old courageously came out himself in 2018 and has been fighting to make the sport more inclusive for years.
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Martin's inspiring announcement happened when he was on the books at MLS side Minnesota United.
And at the time, he was the only only male professional athlete in the major American sport leagues to do so.
Now playing in the USL Championship, Martin shared his hopes that the World Cup can prove a watershed moment for inclusivity in sport.
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England's Harry Kane will be among the team captains wearing rainbow coloured armbands in support of the LGBTQIA+ community.
Meanwhile, Martin's US compatriots have sported a rainbow-themed logo at their training facility in Qatar.
Speaking in an exclusive interview with talkSPORT.com back in July, Martin said: "It's a huge opportunity for the world to make it clear to countries and governing bodies that are hosting huge tournaments that these tournaments need to be inclusive for everyone.
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"I think American and English audiences and especially the sport world have a huge responsibility to make sure that the fans that are going to these games are comfortable and supported and that they are able to be completely themselves at these games.
"But also, I wonder if there's a a closeted player in the World Cup, like how is he going to feel walking out onto a field and is he going to be comfortable enough playing?"
Qatar have faced accusations concerning the treatment of migrant workers and a poor record of human rights since they became hosts.
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Homosexual activity is a criminal offence in Qatar, punishable with a jail sentence, while same-sex marriages are not recognised by the government.
FIFA president Gianni Infantino has insisted "all are welcome in Qatar", yet a Qatar World Cup ambassador has described homosexuality as 'damage in the mind'.
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Martin added: "In terms of the bigger look outlook of the World Cup, there needs to be federations standing up against any type of forms of discrimination if that happens at the World Cup, I personally hope it doesn't.
"I hope it can only be a time to bring more awareness to a country maybe that has lacked diversity or has lacked awareness about the LGBTQIA+ community and human rights.
"I think it can be a great opportunity to educate a lot of people and to bring awareness to these things.
"There potentially might be a closeted player in the World Cup coming up this year.
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"We need to make sure we foster supportive environments so that player, when the time is right, they could potentially share that and be comfortable with their sexuality."
Unfortunately, few players have followed Martin's lead in feeling comfortable enough to publicly come out.
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Part of that may be due to research from BonusFinder.com that found nearly one in five American sports fans say professional players should hide their sexuality or gender identity.
Martin has also come across homophobic abuse while playing - with Junior Flemmings banned for six games in 2020 for using a slur against him.
San Diego were beating Phoenix Rising 3-1 at the time and needed the win to remain in the USL Championship playoff hunt yet Martins' teammates and manager - US icon Landon Donovan - took a knee at the start of the second half before walking off the pitch.
Although Martin told talkSPORT this summer that he was moved by the gesture, the former USMNT under-20 international was unsure whether teams in Qatar should follow suit.
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He said: "That's a hard question. I guess it would depend on what's happening in the stadium but I abuse of any kind just should not be tolerated.
"I think in the world game, not only not even in Qatar, in other countries, there's abuse that is happening towards players, whether it's racial abuse or I'm sure homophobic abuse is happening in all parts of the world, I think it needs to be dealt with and taken seriously.
"Obviously, for me, I had a personal experience where my teammates took the decision to walk off the pitch two years ago.
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"And if you would have told me that would happen before the game, I would have told you that there's no way.
"But I think it took a lot of courage from my teammates in the moment to make that decision and support me.
"So when I was in a really hard moment and was being discriminated against, I needed not only my teammates but a coach and in a club that was extremely supportive and supportive of me."
Collin Martin, San Diego Loyal soccer player, who came out as gay in 2018, has partnered with BonusFinder and LGBT HERO to understand representation and attitudes towards the LGBTQIA+ community in US professional team sport.
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