South Africa lock Franco Mostert was sent off after 12 minutes in last weekend's win over Italy
South Africa assistant coach Mzwandile Stick claims the Springboks have been treated unfairly following red-card incidents in their wins over France and Italy.
Lood de Jager was handed a four-game suspension after being sent off for a high tackle on France full-back Thomas Ramos in Paris, while Mostert was given a straight red card for a shoulder-to-head challenge on Italy's Paolo Garbisi in Turin last weekend.
Mostert faces a World Rugby disciplinary hearing this week, with Stick confirming the world champions have appealed against De Jager's ban.
"Every week we are losing players and it's sad," Stick told reporters in Dublin before South Africa's Test against Ireland on Saturday.
