Varlas Nikos of EuroHoops reported the update Friday.
The 21-year-old Athens native made two appearances for Dallas while on a two-way contract. He averaged 10.6 points, 6.2 rebounds and 1.3 blocks while shooting 52.2 percent from the field across 40 games for the G League's Texas Legends.
Last July, he spoke with Justin Tinsley of The Undefeated about his sibling rivalry with Giannis and his other older brother, Thanasis Antetokounmpo, who recently joined the Bucks.
"I told [Giannis] I'm gonna try to bust his ass," Antetokounmpo said with a laugh. "I say that to all my brothers. We always say, if we play against each other, the only thing we'll do is maybe let them score one time. Then after that, I'm locking him up."
He'll likely split time between the NBA and G League if he sticks with Toronto after training camp.