Burger Odendaal has been ruled out for two months after breaking his arm in the Blue Bulls victory over Griquas at the weekend.
His absence leaves coach Frans Ludeke with a selection dilemma heading into the match against Western Province at Newlands this weekend.
Jesse Kriel replaced him in the 49th minute on Saturday, with William Small-Smith shifting to inside centre for the remainder of the match. Ludeke also has the option of playing Handré Pollard at No 12, although he is likely to want his star flyhalf operating in the pivot position.
In a further blow for the Bulls, scrumhalf Piet van Zyl remains a doubt for the semi-final after suffering an ankle sprain. He will undergo physiotherapy this week, and a call will be made on his participation on Thursday.
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