Ireland head coach Andy Farrel said he is devastated at the loss of veteran prop Cian Healy, who is set to miss the upcoming Rugby World Cup.
Ireland beat Samoa 17-13 in a rainy Bayonne on Saturday night but celebrations were dampened by Cian Healy's injury scare.
Both the Springboks and the All Blacks have a chance to take over from Ireland at the top of the world rankings this weekend, although the Boks have a much harder task.
Billy Vunipola has been banned for the start of England's World Cup campaign after receiving a three-week suspension for his red card against Ireland.
England suffered a 29-10 defeat at the hands of Ireland, as their World Cup preparations hit another snag, after Billy Vunipola was shown a red card.
Caelan Doris shone and Jack Conan suffered an injury scare as Ireland launched their World Cup warm-up fixtures by easing to a 33-17 win over Italy in Dublin.