Arash Markazi of ESPN provided the update Tuesday.
Robinson last played in the NBA during the 2015-16 season when he made two appearances with the New Orleans Pelicans.
The 33-year-old Seattle native has since played for teams in Israel (Hapoel Tel Aviv), Venezuela (Guaros de Lara) and the NBA G League (Delaware 87ers). He also had a tryout with the NFL's Seattle Seahawks in June 2016 but didn't get signed.
Last April, he told Nina Mandell of USA Today his competitive fire still burned and he wanted one more chance to prove himself in the NBA.
"I'm not a money guy," Robinson said. "If basketball in the NBA was free, I [would] still play. If the NFL was free, I'd play. Just because I love to play the game. Financially, it's for my family, for my kids. It's not really for me. I don't care about the fame. I would still play. Even if it's soccer, I would play."
Robinson averaged 11.0 points, 3.0 assists and 2.3 rebounds while shooting 36 percent from three-point range across 618 NBA games.
The three-time Slam Dunk Contest champion joins a Tri-State squad that missed the playoffs with a 3-5 record during the BIG3's inaugural season in 2017.