A football player coming out as gay doesn't change anything. They will still be the same person they always were. All what happens when famous people come out the closet these days is it creates hype of how some how it will change everything and is some kind of break through for man kind. In most cases everyone already knows or assumed they already are gay. If someone is "coming out the closet" they're saying their sexuality and by making out it's a big thing and creating high hype about it like making out they have the plague it creates a bigger gap between sexualities.
When LGBT identifying teens are 40% more likely to commit suicide, compared to their heterosexual peers, I don't think you can write off something like this so easily. Having a premier league footballer out and proud would be a very good thing in terms of teens having someone to relate to. Being in the closet can be so isolating, and having someone you can identify with makes such a difference.