The Blues rugby coach Pat Lam says first-five Luke McAlister will miss Saturday night's Super 15 match against the Crusaders in Auckland and Stephen Brett will start at 10.
McAlister was concussed early in his side's pre-season draw with the Chiefs in Pukekohe.
Lam says a back-up number 10 won't be a problem if McAlister doesn't recover in time for the second round.
But he says there's a good chance the former All Black will be available for the Sharks match in Durban.
Lam says McAlister's being tested every day and they'll have a better idea by Thursday or Friday.
If he can't travel there'll be backup available for Stephen Brett from the Blues' wider training group as Auckland has a team on a two match tour of South Africa.
