Smith made 142 in Australia's second innings 487-7 declared on Sunday after the star batsman's 144 bailed them out to 284 following a collapse to 122-8 in their first innings.
The decision, taken during a board meeting last week, follows a disastrous South African World Cup campaign in which the Proteas finished seventh of the 10 teams.
Cyrus Christie, who came on as a substitute in the former Premier League side’s first match back in England’s second tier, took to Twitter after the game to call out the instigators.
Paul Pogba said in June that he could seek a new challenge after three years at United, while his agent told 'The Times' last month that the 26-year-old intends to leave the club amid reports linking him to Juventus and Real Madrid.