New Zealand coach Scott Robertson rang the changes for their Autumn Nations Series clash with Wales, bringing in 13 fresh faces to the run-on XV that lost to England last week.
Mostert is now free to face Ireland in Dublin on Saturday in the Boks' final Test of the year with the four-time Rugby World Cup winners already without fellow lock Lood de Jager.
Barcelona will open the Camp Nou against Bilbao with a temporary capacity of 45,401 spectators, with space for 105,000 when the top tier is eventually completed.