Sullinger, 29, is 6-foot-9 and spent last season with South Korean club Anyang, averaging 27 points and 12.2 rebounds, Carchia relayed.
Prior to signing in South Korea, Sullinger had not played since the 2018-19 season, when he also played with Shenzhen.
He was originally was drafted by the Celtics with the 21st overall pick in the 2012 draft following a successful career at Ohio State. But back issues have plagued Sullinger for most of his pro career.
After four years with the Celtics, Sullinger played his most-recent NBA season with the Raptors in 2016-17. He carries NBA career averages of 10.8 points and 7.5 rebounds.