Jerome Kaino will undergo knee surgery but the New Zealand flanker is expected to be fit to face the British and Irish Lions.
Blues will be without Kaino for up to six weeks after he suffered a slight meniscus tear in his knee during the 28-24 Super Rugby defeat to Hurricanes last weekend.
It is anticipated that the 34-year-old loose forward will be back to full fitness in time for the three-match series against the Lions, which starts at Eden Park on June 24.
Blues assistant coach Steve Jackson said: "He's got a lot of big things coming up towards June so now was the time to get it done.
"And again, he was feeling it and as I said before it was locking up on him so potentially he could have played with some discomfort then if it locked up during game time we would have to replace him anyway."
Jackson added: "He'll get his feet up and normally you come back quick from those sorts of operations. I'm pretty sure he'll be fine for the Lions tour."
Maori All Black loose forward Akira Ioane will replace Kaino in the Blues starting line-up when they take on Brumbies in Canberra on Sunday.