New Zealand vice-captain Richie McCaw is expected to be out for up to three weeks after being knocked unconscious while playing for the Crusaders in the Super 12.
McCaw was knocked out while trying to tackle Bulls prop Richard Bands on April 10.
The Crusaders skipper has been in training but coach Robbie Deans plans to leave him out until he is sure he has recovered.
McCaw suffered recurring headaches after being knocked out in a Test match against England last year.
Meanwhile, Crusaders lock Norm Maxwell is out with a broken and dislocated finger but should be available for the British & Irish Lions tour.
