Robbie Fruean will miss the Chiefs' three match road trip after needing a heart procedure which will put the centre out of action for up to eight weeks.
The 25-year-old, who underwent his second heart surgery last year, will be having an ablation procedure for an arrhythmia and will remain in New Zealand. He faces 4-8 weeks on the sidelines.
Fruean's rugby career was temporarily curtailed in 2009, with open heart surgery required after a bout of rheumatic fever caused pancarditis, or inflammation.
Sixty-one caps for the Crusaders later, Fruean noticed early last year his cardiac function was weakening. Further surgery was needed in July and the original valve was swapped for a larger version, ruling him out of the remainder of the season.
After successful surgery and with non-contact training having progressed to full sessions, Fruean returned to action in his Chiefs debut in week two - an 18-10 win over his former club.
He has made two starts for the Chiefs and came off the bench in his side's 36-20 win over the Stormers on Friday night.
Meanwhile winger James Lowe damaged his MCL knee ligament and is expected to be out of action for 4-6 weeks.
Ben Afeaki, Sam Cane and Augustine Pulu move off the injured list to join the travelling group and will be joined by wider training squad members Brad Weber, Anton Lienert-Brown and Jordan Payne.