NBA star Ricky Rubio is ending his professional basketball career ... revealing he made the decision after going into "a dark place" last offseason.
33-year-old Rubio -- the fifth-overall pick in the 2009 NBA Draft -- spent 12 seasons in the Association ... most notably for the Minnesota Timberwolves, where he played from 2011-17.
The Spanish guard joined the Cleveland Cavaliers in 2021 ... but it was announced back in August he would take time away to focus on his mental health.
On Thursday, Rubio shared a statement on his official retirement ... sharing July 30 was "one of the toughest nights of my life," but did not go into detail.
"I kind of knew I was going on that direction, but I've never thought I wasn't under control of the situation," he said.
"The next day, I decided to stop my professional career."
Rubio said he will talk more on what happened at a later date so he can help others going through similar situations ... and will continue to work on his mental well-being moving forward.
"But I am proud to say I'm doing much better and getting better everyday," he added.
Rubio -- who averaged 10.8 points, 4.1 rebounds and 7.4 assists in his career -- said it was a dream to play in the NBA ... thanking the Wolves, Utah Jazz, Phoenix Suns and Cavs for "good memories and great relationships."
He also sent a special message to Cleveland ... thanking the organization for being "extremely respectful and understanding" of his situation.