Carlos Ramos has not worked any of Williams' matches since he docked her a game in the final against Japan's Naomi Osaka for calling him a "liar" and a "thief."
Ramos called three code-of-conduct violations against Williams in the match she eventually lost to Osaka after ruling she illegally communicated with her coach during the match.
USTA chief executive Stacey Allaster told the New York Times that officials didn't want to cause a distraction by putting Williams and Ramos on the same court.
Williams was fined $17,000 by the US Open for her actions, which also included smashing her racket. Ramos was not disciplined and received the full backing of the International Tennis Federation after the incident.
Williams will face former world No. 1 Maria Sharapova in her first-round match on Monday.