4:17pm: Jackson’s signing is official, the Celtics announced in a press release.
Jackson has been playing for the Texas Legends, Dallas’ NBA G League affiliate.
The 15th pick of the 2017 draft, Jackson has appeared in 248 NBA games. Last season, he played 33 games for the Thunder and another for the Bucks. He began his career with Sacramento and also played one full season and part of another for Dallas.
The Mavericks waived Jackson during training camp prior to this season.
Boston has a handful of players in the league’s health and safety protocols — Sam Hauser, Juan Hernangomez, Al Horford, Jabari Parker and Grant Williams. The exemption is being used by multiple clubs to handle the current COVID crisis around the league. Players signed via the exemption don’t count against the 15-man roster limit.