Koster is the third loose-forward casualty joining Schalk Burger and Duane Vermeulen on the sidelines. He also follows Gio Aplon and Jean de Villiers back home as injuries are starting to threaten the Stormers campaign.
Nick Koster aggravated a knee injury in training this week. He will be assessed by a specialist on his return.
Commenting on the injuries coach Allister Coetzee said, “Despite the injuries, the touring group is in high spirits and is very motivated.”
“Our motto for the week is; nothing special has ever been achieved in ideal conditions. A win this week will be the difference between a good tour and a great one and this group knows that. Our sessions this week have been excellent and we will be going all out for a win in this game.”