NBA journeyman and former Celtics center Jason Collins will officially announce his retirement from the NBA tonight at the Barclays Center as the Brooklyn Nets take on the Milwaukee Bucks.

18 months ago, Collins made headlines for being the first male athlete to come out as gay in one of the four major U.S. sports. While he was a free agent at the time, he was signed to a contract by the Brooklyn Nets late in February, making him the first openly gay player to play in an NBA game. In a column in Sports Illustrated, the same publication in which he came out to the public, Collins, in his own words, wrote about his plans to end his career tonight, and is glad that he’ll have the opportunity to do so in the company of friend and supporter, Jason Kidd.

“The day will be especially meaningful for me because the Nets will be playing the Bucks, who are coached by Jason Kidd, my former teammate and my coach in Brooklyn. It was Jason who cheered my decision to come out by posting on Twitter: ‘Jason’s sexuality doesn’t change the fact that he is a great friend and was a great teammate.”

Collins has been in the NBA since 2001, having played with six different teams throughout the course of his career, including the Celtics in the 2012-13 season. After coming out in April of 2013, once the NBA regular season had ended, Collins became an enormous figure in the LGBT rights movement. He was featured on the cover of Time Magazine’s “100 Most Influential People in the World” issue, and when he made his return to the court on February 23, 2014, The Staples Center gave him a powerfully warm round of applause and he stepped on the court wearing number 98– a tribute to Matthew Shepard, who was killed in 1998 in what was widely believed to be a hate crime.

Collins leaves the NBA floor tonight, but with it, leads a movement of greater acceptance in professional sports.

“When we get to the point where a gay pro athlete is no longer forced to live in fear that he’ll be shunned by teammates or outed by tabloids, when we get to the point where he plays while his significant other waits in the family room, when we get to the point where he’s not compelled to hide his true self and is able to live an authentic life, then coming out won’t be such a big deal. But we’re not there yet.”

[h/t Sports Illustrated]