The young flyhalf has burst onto the international scene this season, stringing together several virtuoso performances and grabbing headlines for all the right reasons.

But Feinberg-Mngomezulu was left out of coach Rassie Erasmus' Bok squad for the one-match trip to Argentina for the Rugby Championship and on Tuesday, fans found out why.

"Sacha will only be ready for the end-of-year tour," revealed the World Cup-winning coach.

"He injured his knee before the first Test against the All Blacks and he played in that game. The next week on the Wednesday, I asked him why he was limping and he said he injured his knee last week. I wanted to pull him out of that team because he was limping, on the field even.

"And that's what our players must understand. We have respect for everybody, but we must be honest when it comes to injuries.

"Nobody who's got an injury and 80% ready, is better than a Springbok who has no injuries and is 100% ready. So Sacha is lucky that we won those Test matches because he gambled a bit.

"He is having the operation now. I'm not sure exactly what is wrong with the knee but he will only be ready in four and a half weeks."

The Boks have pivots Handre Pollard and Manie Libbok in the current squad, with Damian Willemse set to make his return in the Stormers jersey domestically in the weeks to come following finger surgery.

READ MORE: Springboks ring the changes for Rugby Championship clash against Argentina

Teams	M	W	L	PTS	NET RR
Boland	7	5	1	25	0.565
Dolphins	7	4	2	23	0.305
Titans RSA	7	4	2	21	1.012
Warriors RSA	7	4	2	16	0.692
Knights	7	3	3	16	0.578
Lions	7	2	4	10	-0.595
North West	7	2	5	9	-1.295
Western Province	7	1	6	5	-1.068

Finished CSA Provincial One-Day Challenge Division One