Chiefs' flyhalf Aaron Cruden will miss six to eight weeks of Super Rugby after fracturing his thumb in a dramatic 43-all draw with the Cheetahs.
The injury could potentially be a major dent to the Chiefs' hopes of securing three titles in a row.
The franchise said in a statement on Monday that the 25-year-old had an X-ray following the draw in Bloemfontein - the results of the scans confirming that his left thumb was fractured.
The estimated recovery period also puts Cruden in doubt for the opening match of New Zealand's three-Test series against England, which begins on June 7 in Auckland.
He is regarded as the heir apparent to Dan Carter, who is currently unavailable for the Crusaders and the All Blacks - as he enjoys a sabbatical designed to extend his playing career through to next year's World Cup.
If both Cruden and Carter are absent, Hurricanes' Beauden Barrett is regarded as the next most likely candidate to play pivot against England, although he has only 16 Test caps, 14 of them from the bench.