Jefferson signed a contract Tuesday with Galatasaray S.K. of the Turkish Super League.
Jefferson was waived by the Celtics on Saturday, Jared Weiss of The Athletic reports.
Jefferson supplied 30 points (14-22 FG, 0-1 3Pt, 1-4 FT), 11 rebounds, four assists, two steals and two blocks in 39 minutes during Tuesday's win over Erie.
Jefferson provided 19 points (7-9 FG, 4-8 FT), 11 rebounds, three blocks and two assists in 27 minutes during Saturday's win over Grand Rapids.
The G League Magic acquired Jefferson via the avilable player pool Friday.
Jefferson will be waived by the Magic on Thursday, Josh Robbins of The Athletic reports.
Jefferson recorded 22 points (9-16 FG, 2-4 FT), 15 rebounds, two assists and a block in 37 minutes during Thursday's win over South Bay.
Jefferson was recalled from Lakeland of the G League and will be available for Orlando's contest against the Lakers on Wednesday.
Jefferson was assigned to Lakeland on Tuesday.
Jefferson was recalled from the G League's Lakeland Magic and will be available for Orlando's game Sunday against Washington.