Australian soccer player Josh Cavallo, a midfielder for Adelaide United, came out as gay over social media early Wednesday to become the only men's top-level soccer player to be publicly out. "I'm a footballer and I'm gay," the 21-year-old athlete said in an emotional Twitter video reading his coming-out story. Cavallo's international coming out follows a wave in American sports over the past four months that's seen three publicly gay athletes out in the top four professional sports – Carl Nassib (NFL), Luke Prokop (NHL minors) and Bryan Ruby (pro baseball minors). Cavallo's team, Adelaide United is in the top Australian soccer league, A-League Men. The league tweeted its support of Cavallo and fellow out Australian soccer player Andy Brennan.