The Stormers 39-26 victory over the Hurricanes came at a price as captain Schalk Burger will miss the next six weeks.
Burger was driven off the field on the medical buggy after fifteen minutes and immediately went for scans on his knee.
Burger fell awkwardly on his knee while being tackled in the 14th minute.
The scans revealed that Burger has torn his medial ligament and the early medical report is that he will be out of rugby for four to six weeks.
As Burger is Stormers captain and crucial to the success of their campaign in Super Rugby coach Allister Coetzee is unlikely to take any chances and rush him back.
"Unfortunately we've lost the captain (for the next few matches)," said Coetzee. "He's torn his medial ligaments so he'll be out for four to six weeks.
Burger was scheduled to see a specialist on Sunday.
On a positive note there was a measure of cheer in the Stormers dressing room when they heard the news that flyhalf Peter Grant, who no longer has club commitments in Japan, was on his way back to Cape Town.
Grant will however have to go through fitness tests before being named in the side to play the Sharks at Newlands next Saturday.
"First I have to do a medical assessment to find out of Grant has any niggles," said Coetzee.
"And I need to be fair to him and allow him to settle down after the trip from Japan.
" I not saying he won't be considered but there are many factors that I'll have to consider before I make a selection call."