Minnesota United player Collin Martin has become the only publicly gay male athlete active in the United States' five major professional leagues.

MLS midfielder Martin released a personal message on Twitter revealing he will share the news for the first time to the public during Minnesota United's Pride Night on Friday, although many of his team-mates were already aware of his sexuality. 

"I have been out as a gay man for many years to my family and friends, and this includes my team-mates," Martin wrote in a statement. 

"I have played Major League Soccer for six seasons: four seasons with DC United and two seasons with Minnesota United. Today, I'm proud that my entire team and the management of Minnesota United know that I am gay.

"I have received only kindness and acceptance from everyone in Major League Soccer and that has made the decision to come out publicly that much easier. As we celebrate Pride Night, I want to thank my team-mates for their unconditional support for who I am.

"In light of my experience as a professional athlete, I want to take this moment to encourage others who play sports professionally or otherwise to have confidence that sport will welcome them wholeheartedly.

"June is Pride month, and I am proud to be playing for Pride, and to be playing as an out gay man."