The Bulls hopes of winning a Super Rugby title have suffered a severe blow as Captain Pierre Spies has been ruled out for the rest of the 2013 season.
Spies tore a bicep muscle on Saturday while playing for the Springboks against Samoa.
Spies saw two specialists, one in Johannesburg and one in Pretoria for opinions and ultrasound scans revealed the damage and he will be operated on today.
According to Bulls team doctor Org Strauss, this operation will rule Spies out for the remainder of the season including the Rugby Championship and the Springboks end of year tour.
The Bulls have not said who will take over the captaincy in Spies' absence.