The announcement was made official by his agent, Andy Miller, via Twitter, on Friday.
— ASM SPORTS (@ASM_SPORTS) June 20, 2014
Blatche had told reporters on breakup day that he intended to opt out, so the move comes as no surprise.
The 27-year-old held a player option with Brooklyn for 2014-15 for just $1.4 million.
Blatche is now free to sign with any team.
The Nets have Blatche’s early Bird rights, meaning they’d be able to offer him a new deal for as much as four years, $25 million.
Blatche is due $8.4 million in amnesty payments from the Washington Wizards in 2014-15.
Blatche has been terrific coming off the bench the last two seasons for Brooklyn.
In 2013-14, he averaged 11.2 points and 5.3 rebounds, while shooting 47.6 percent from the field. Blatche did struggle in the playoffs, though, averaging just 6.4 points on 44.8 percent shooting in 14.3 minutes.
Garnett could elect to retire, however, although he is currently on the books. Lopez is coming off season-ending foot and ankle surgeries.
Should Garnett, Pierce and Kirilenko all decide to come back, playing time could be hard to come by, and the Nets may decide to move on, with Blatche finding greater opportunity elsewhere.