One I would say is Rashad McCants, he was great at North Carolina and was drafted as the fourteenth pick in the 2005 draft. His first two years were rough due to injuries, then in his third season he started doing good. He averaged 15 points per game but was traded from Minnesota to Sacramento the following year. He had another good year up until his contract expired and he vanished. He hasn’t been seen in the NBA since 2009. What other NBA players randomly or suddenly disappeared?
Someone beat me to it