Cillar O'Neal died this week. Funeral services are in New Jersey.
O'Neal will be replaced by rookie Robin Lopez at center for the nationally televised game (10:30 p.m. ET, ESPN).
O'Neal said he hopes to return in time for Friday night's home game against Orlando.
O'Neal scored 35 points, grabbed eight rebounds, and blocked three shots in Tuesday's win by the Suns over Milwaukee.
Information from The Associated Press is included in this report