On February 23, 2014, Collins signed a 10-day contract to rejoin the Nets, who had since moved to Brooklyn. Nets coach Jason Kidd, who became good friends with Collins while teammates in New Jersey from 2001 to 2008, was an advocate of signing Collins. Collins played 11 minutes that night against the Lakers at the Staples Center, becoming the first publicly gay athlete to play in any of the four major North American professional sports leagues. Collins wore jersey number 46 (the only number the team had available at the time) in his first game of the season, but planned to wear No. 98—the same number he wore with Boston and Washington—going forward. Collins chose to wear No. 98 in honor of Matthew Shepard, whose 1998 murder was widely reported as a hate crime and ultimately led to the passage of the Matthew Shepard and James Byrd Jr. Hate Crimes Prevention Act. Collins' jersey rose to the top spot for sales in the NBA's online shop, and the NBA announced that proceeds from the sales, as well as proceeds from auctions of Collins' autographed game-worn jerseys, would benefit the Matthew Shepard Foundation, and the Gay, Lesbian & Straight Education Network (GLSEN).
On March 5, 2014, Collins signed a second 10-day contract with the Nets. On March 15, 2014, Collins signed with the Nets for the rest of the season.
On November 19, 2014, Collins announced his retirement from professional basketball after 13 seasons in the NBA.
Since June 2014, Collins has been in a relationship with producer Brunson Green.