The Chiefs centre Robbie Fruean will have another procedure on his heart and he'll be out of action for up to two months.
Fruean, along with Charlie Ngatai and James Lowe, who were injured playing against the Stormers on Friday night, have been left out of the 27-man squad named to travel to Perth and South Africa for their next three Super Rugby matches.
Fruean will be having an ablation procedure for an arrhythmia, the same procedure that rugby player Gus Collins and former rower Rob Waddell have had.
Fruean had his second open-heart surgery last year.
Meanwhile centre Ngatai will be out for up to six weeks with a calf injury and winger Lowe is out for a similar time following damage to his MCL knee ligament.
Ben Afeaki, Sam Cane and Augustine Pulu return to the squad after injury.
The Chiefs will play the Western Force, Bulls and Cheetahs on tour.