The Lions camp revealed on Monday fullback Jaco van der Walt sustained a grade III PCL injury of his right knee and will be out for about six weeks.
It is the second fullback the Lions have lost after Andries Coetzee injured ankle ligaments earlier in the campaign.
It was further stated that flyhalf Elton Jantjies fractured a dislocated finger and was due to see a hand surgeon later today.
Another injury concern is that of prop Corne Fourie who injured a rib cartilage and will undergo a late fitness test this week.
It is third injury Jantjies suffered in the last few weeks with first a cracked wrist, followed by a knee injury and now a dislocated finger.
And with him at the centre of their attacks launched at the back he is become an integral part of the team while he is the frontrunner to wear the Springbok jersey against Ireland next month.
Either Ross Cronje or Marnitz Boshoff could be filling in for Jantjies is he can’t play against the Bulls at Loftus this weekend, while Sylvian Mahuza or JW Bell could be called upon to wear the No 15 jumper.