on january 17, 2013, mack signed a 10-day contract with the philadelphia 76ers. on january 28, he signed a second 10-day contract with the 76ers. he was not retained by the 76ers following his second 10-day contract, and on february 7, he was reacquired by the red claws. he went on to play for the futures all-star team in the 2013 nba d-league all-star game.