Marcell Coetzee has been ruled out for four months after his knee injury was confirmed as a meniscal cartilage tear.
Coetzee suffered the injury in a recent match between Ulster and Zebre, and while it was initially feared that he may have ruptured his ACL again, exploratory surgery found that it was not quite so serious.
The loose forward will miss the rest of the European season, but should be able to complete a full pre-season programme with a view to being fully fit at the start of Ulster's 2017-18 campaign.
However, it is bad news from a Springbok perspective, as Coetzee will not be available for the June series against France.
The former Sharks flanker currently has 28 Test caps to his name, and it was hoped that he would be able to feature against France to reach the new 30-cap eligibility ruling for overseas-based players, which comes into effect from July.
Photo: Ulster Rugby