NBA player Jason Collins came out as gay in Sports Illustrated this week. Reaction to his announcement has been largely positive. Melissa Block speaks with former tennis great Martina Navratilova about Collin's decision to come out, and Navratilova's own experience after she came out over 30 years ago. MELISSA BLOCK, HOST: When the seven-foot tall NBA center Jason Collins came out yesterday in Sports Illustrated revealing that he's gay, he got a statement of praise from former President Bill Clinton and a phone call from President Obama, who talked about Collins at today's White House news conference. (SOUNDBITE OF NEWS CONFERENCE) PRESIDENT BARACK OBAMA: He seems like a terrific young man and, yeah, I told him I couldn't be prouder of him. BLOCK: Jason Collins becomes the first openly gay active player in a major American men's team sport. And tennis great Martina Navratilova calls him a game changer. She herself came out way back in 1981, and she joins me from Miami to talk about this moment and what it means. Martina Navratilova, welcome to the program. MARTINA NAVRATILOVA: Thanks for having me. Thank you so much.