Springbok star Pieter-Steph du Toit was at risk of losing his leg after suffering an injury in the Stormers' 33-14 defeat to the Blues late last month.
In a startling revelation, the reigning World Player of the Year was rushed to hospital in South Africa after being replaced in the 67th minute of the match.
After being assessed by team doctor Jason Suter, it became apparent that a haematoma in du Toit's leg had become something far more rare.
The flanker had suffered acute compartment syndrome, which can cut off the blood supply if it is not detected early.
"He had a medical emergency after the Blues game," team doctor Sutor is quoted as saying in Sport24.
"He had a haematoma that developed into an acute compartment syndrome. It's incredibly rare - there have been only 43 cases listed in the literature," Suter said.
"It's a medical emergency because if you don't pick it up early they lose blood supply to the leg and they lose the leg.
"Within 15 minutes of him coming off the field and assessing him, we realised that he was at risk of this particular rare condition. He was taken straight to Vincent Pallotti Hospital where he had a vascular surgeon waiting and he was operated on that night.
"It's very unusual, very rare but they had to cut through the muscle to release the pressure and they were only able to close that leg 10 days after his initial injury."
"He is recovering well and we expect him to be back, based on the surgeon's report, at around three months."
Du Toit is expected to be out of action for around three months but, clearly, the situation could have become far more serious.
Head coach John Dobson added: "Doc deserves enormous credit for Pieter-Steph, had a rugby player lost his leg it would have been devastating for the game. And if it wasn't for the timely intervention then I think (he could have lost his leg)... almost half of the 43 reported cases had resulted in that."
