In a statement released Saturday afternoon, GM Elton Brand brought to light "inappropriate and offensive social media posts from Bob Muscala," the father of forward Mike Muscala.
Bob Muscala had been operating a burner Twitter account under the name "MuskieBobber," a team source confirmed to both the Philly Voice and ESPN. Past tweets made by the account included racist messaging to criticize the Jimmy Butler situation with the Minnesota Timberwolves.
"Simply put, they are unacceptable and in no way reflective of the beliefs of our organization," Brand said of the tweets.
The account has since been deleted.
Mike Muscala, who was acquired via trade this offseason by the Sixers after five seasons with the Hawks organization, apologized for his father's posts.
"His comments were uncalled for and inappropriate, and they do not reflect who I am," said Muscala, who also applauded the "professionalism and support shown by Elton, Coach [Brett] Brown, my teammates and the entire 76ers organization" while dealing with the situation.
Philadelphia hired Brand as its GM last month, a move necessitated when Bryan Colangelo resigned in June after his wife admitted to operating Twitter accounts that criticized team members and propped up her husband.
"This situation is also a reminder to our players, coaches and staff of the potential impact — both positive and negative — of social media," Brand said Saturday. "We will use this situation to once again review, monitor and discuss appropriate social media usage across all areas of our organization."
ESPN's Ian Begley contributed to this report.