The 6-foot-10 forward has averaged 3.3 points and 4.3 rebounds over 12 minutes per contest in three appearances. His second 10-day contract expired after Wednesday's loss in New Orleans and Celtics coach Doc Rivers had previously noted the team would bring him back to maintain continuity.
The injury-depleted Celtics signed three former Chinese Basketball Association players to 10-day deals in Randolph, Terrence Williams and D.J. White. All three have since been inked for the remainder of the season with options that give them a chance to stick beyond this year.
Boston is at the 15-man roster limit.