The Sharks flank was forced from the field in the early minutes of the game but was able to stand and walk off on his own accord.
But South Africa’s Independent Newspapers group reported that the World Cup-winning flanker suffered a partial ACL tear that typically involves a 9 month recovery process if surgery is undertaken.
The report said that Kolisi has seen two specialists who have recommended surgery, and a third will be consulted before a decision is made.
If he has to go under the knife to repair the damaged ACL it would put his World Cup campaign in doubt which begins on September 8, a little over four months away.
The news is devastating for the inspirational figure who led his country to World Cup victory in 2019.
Kolisi is set to join French powerhouse Racing 92 in the Top 14 at the conclusion of the World Cup but would still be eligible to represent the Springboks as an overseas-based player.
With or without surgery, Kolisi is sure to miss the Springboks reduced Rugby Championship campaign which begins in July with a Test at home against the Wallabies.
They travel to New Zealand to face the All Blacks before two Tests against Argentina, one outside the Championship, before meeting the All Blacks again in a pre-World Cup clash at Twickenham.