Australian professional footballer Josh Cavallo said he has “never smiled so much in my life” and had “the best night’s sleep” after publicly revealing he is gay.

The Adelaide United midfielder, who has represented Australia at under-20 level, is the only known current male top-flight footballer to be out.

Speaking to BBC Breakfast on Thursday, the 21-year-old said: “Today I woke up and closed that old book and opened the real book on Josh Cavallo.

“I never smiled this much in my life, and I had the best sleep last night knowing that I could finally be myself, and not lead a life of lies to the people I care about the most.

“My cheeks are very sore today but it is a good thing to have.”

Cavallo announced the news in a social media post on Wednesday ahead of the forthcoming A-League season.

He added: “When I was growing up at as a kid and dreaming of being a professional footballer, I did know I was gay, and I really struggled with my sexuality.

“It was something I was scared to do. I did not want to play football and be gay because I had never seen that done before. I feel the pain of that little kid and I still feel that pain today.

“In the normal world, being gay is fine and I want to make that fine in football.

“There are very talented kids out there who are potentially gay, and who could be the next (Cristiano) Ronaldo or (Lionel) Messi, and they stop and they turn away because they are scared they will be treated differently.

“I want to tell my story to the younger generation and the people going through what I am going through, stuck in that shadow and see that it is OK and that there is no need to hide away, but to be a role model to these people – something I didn’t have.”

Cavallo’s announcement was greeted by a series of positive responses, with the likes of Manchester United forward Marcus Rashford, Liverpool captain Jordan Henderson and Barcelona defender Gerard Pique among a host of footballers to show their support.

His club Adelaide United said in a statement: “Today, Josh Cavallo speaks his truth to the world and demonstrates profound courage.

“Adelaide United, not only as a football club, but as the embodiment of an inclusive community, supports a remarkable and brave person.

“We stand alongside Josh for proudly being true to himself and will continue to love and support him as a member of our beautifully diverse family.”