Among the teams Jason Collins has played for are the Boston Celtics.

Jason Collins has rejoined the Nets with a difference: He becomes the first openly gay athlete in any of America’s four major sports.

There’s lots of symbolism here: The team now plays in Brooklyn, where Jackie Robinson broke the color barrier in baseball. The Nets are owned by Mikhail D. Prokhorov, from Russia, which has taken a tough anti-gay stance. And Collins will wear his regular No. 98, in honor of Matthew Shepard, the college student who was murdered for being gay in 1998.

Collins may soon be joined in pro sports by Michael Sam, who’s just come out and is on-target to be drafted by the NFL.

All of which makes me look prescient for publishing “Water Music,” a novel about four gay athletes and how their shifting rivalries color their personal relationships with one another. (The second novel in “The Games Men Play” series, “In This Place You Hold Me,” is about a gay quarterback’s search for identity and is due next year.)

The athletes in my books struggle with coming out, partly because this creates literary conflict, partly because I’m not convinced that everyone in the NBA and the NFL who’s now talking the tolerant talk will wind up walking the walk. (Certainly, the homophobic, racist, sexist, misogynistic crap that came out of the recent report on Richie Incognito’s hazing of Jonathan Martin when both played for the Miami Dolphins is dismaying.)

But let’s be glass-half-full types, shall we, remain cautiously optimistic and say God speed, Jason Collins and Michael Sam.