FROM CNN WIRES:

(CNN) - It's the biggest move of his career and it's off the court.

Jason Collins, who played with the NBA's Boston Celtics and Washington Wizards this season, has disclosed that he is gay, making him the first active openly gay male athlete in the four major American pro team sports.

The center, who said he is now a free agent, made the disclosure in a column appearing in the upcoming issue of Sports Illustrated.

"I didn't set out to be the first openly gay athlete playing in a major American team sport. But since I am, I'm happy to start the conversation. I wish I wasn't the kid in the classroom raising his hand and saying, 'I'm different.' If I had my way, someone else would have already done this. Nobody has, which is why I'm raising my hand," he wrote.

Collins also wrote that the killing of three people at the Boston Marathon persuaded him to make an announcement. Things can change in a moment, so why not starting living more truthfully, he wrote.

This morning on "Early Start," ESPN's "Mike and Mike" co-hosts Mike Greenberg & Mike Golic weigh in on NBA player Jason Collins announcing he is gay.

READ MORE: NBA's Jason Collins comes out as gay