Marcius, who played at DePaul for one season after transferring from Purdue, was most recently playing professionally in Spain for Sammic ISB.
Sandi started 24 games for the Blue Demons in 2013-14 and averaged 4.8 points and 4.6 rebounds per game.
The 6-10, 255 lb. center played 18.6 minutes per game and shot 60 percent from the field.
Marcius will wear number 55 for the Bulls.
The team will compete in the Las Vegas NBA Summer League and will begin preliminary play on Saturday, July 9th against the Boston Celtics.
Others named to the Bulls Summer League team include: