Bulls fly-half Louis Fouché injured knee ligaments against the Kings and will be out of rugby for at least six months.
The young number ten has been in fine form this season, rotating in the fly-half role along with veteran Morné Steyn.
According to Bulls team doctor Org Strauss, an operation is needed after Fouché ruptured his ACL and he will undergo an operation next week.
Fouché will join Pierre Spies ( bicep) and Arno Botha (knee) for a six-month stint on the side line.
Cornell Hess (knee) is five months away from action, but Paul Willemse (knee) could return to the training field in a week following successful rehab after his knee operation. Lionel Mapoe (shoulder) will return in three months.
Wiaan Liebenberg (AC joint, one week), Hencus van Wyk (ankle, Wednesday) and Ruan Steenkamp (ankle, one week) will all return in the next couple of days.