It's not at all a surprise this individual feels that they cannot come out to the public and must suppress who they as a whole person. It's incredibly sad and disappointing.
However as mentioned already previously, the amount of abuse this person will get from the UK press/tabloids, ignorant and intolerable social media keyboard fecktards, certain sections of supporters and opposing fans, in addition to any foreign fans....they will all target this person. To that, their is a legitimate and real chance that his playing career would have been different and can still be different if they came out too early in their career or now.
They've heard all the jokes and/or insults well before they themselves realized they were gay and now that they are a seasoned professional footballer, they've heard even more homosexual jokes/insults.
I think that this person would also receive much, much more support and empathy from their colleagues, players, staff, etc than they would expect because being gay isn't the end all, be all. They understand and have witnessed that they are a professional, dedicated to their craft, and have made many of the same sacrifices and gone through the same struggles to make it as a professional footballer to the Premier League level. That demands and has earned them a ton of respect because that contributes a lot to who they are as a person.