Blues first five-eighth Ihaia West has been ruled out of rugby for the next four weeks due to an ankle injury.
He suffered the injury in the side's 28-15 win over the Force on Saturday.
West has come off the bench in the last two matches and has scored 49 points this season after starting the season in the 10 jersey.
Bryn Gatland, who joined the Crusaders last month as temporary injury cover, has been called into the Blues squad.
