After college, Simon played five games with the Orlando Magic during the 1999 NBA season. He played for two seasons for the Dakota Wizards of the CBA, whom he led to a CBA championship in 2002. Simon earned enough awards and honors in 2001–2002 to make him the most decorated player in CBA history. He received honors as Player of the Week four times. He was named the CBA Newcomer of the Year, the CBA MVP, and the Playoff MVP. He also holds the CBA record for most free throws made in a row at 60.
In 2005, Simon was announced as an assistant coach under his collegiate head coach Lute Olson at his alma mater winning the conference championship and reaching the Elite Eight in March 2005. He remained an assistant coach until May 2008, when it was announced by the Arizona athletics department that his coaching contract would not be renewed.