All Blacks outside back Israel Dagg needs an operation on his right knee and will be out of all rugby for about six weeks.
An MRI scan after the Crusaders' last-gasp 22-20 win over the Reds in Brisbane revealed a PCL and lateral meniscal injury. A specialist has recommended surgery which has been described as minor.
Another Crusaders' All Black, Seta Tamanivalu, is said to be progressing well from a right upper hamstring injury against the Reds but has been ruled out for a further four weeks.
Former Wallabies wing Digby Ioane has also be ruled out of the match against the Blues in Christchurch on Friday. Ioane has a minor hand injury.
The Crusaders, on a three-match streak to start the season, will look to extend that run against a Blues team who have lost their past two matches.
