Okafor, the second overall pick in the 2004 NBA draft, was in training camp with the 76ers before the club waived him on Saturday.
Okafor, 35, hasn't played in an NBA regular-season game since April 15, 2013, because of a herniated disk in his neck. Okafor, the 2005 NBA Rookie of the Year, was medically cleared to play five months ago.
Okafor has averaged 12.3 points and 9.9 rebounds through nine NBA seasons. As a member of the Delaware 87ers, Okafor is free to sign with any NBA team.