After four years of pro ball overseas, Green earned a spot on the Celtics' roster for the pandemic-shortened 2019-20 season. He went on to appear in 48 of 72 games during the pandemic-shortened campaign, averaging 3.4 points, 1.9 rebounds and 0.5 steals in 9.8 minutes. On Nov. 7, Green put up 12 points in just 13 minutes against Charlotte. He pulled down a season-high eight rebounds on Mar. 3 against Brooklyn. An active presence on defense, Green recorded multiple steals on six occasions, snatching a season-high three on Jan. 24 against the Magic. Boston was one of 22 squads invited to the Orlando bubble for seeding and subsequent playoff games. Green had easily the best game of his young NBA career against the Wizards in the bubble on Aug. 13, the last game of the season. Making his second NBA start and getting the opportunity to play 30-plus minutes for the first time, Green scored 23 points on 8-of-17 shooting, including a trio of three-pointers. The spry wing made his playoff debut as well, scoring three points with one rebound during a Aug. 19 first-round win over the Sixers. A sprained right knee kept Green out of Boston's remaining postseason contests.
July 25, 2019Signed a two-year contract with the Boston Celtics.