Fullback Ben Smith is a doubt for the Highlanders' crunch Super Rugby match against the Crusaders on Saturday after being taken to a Sydney hospital for an infection.
Smith stayed in Australia after his team mates headed home to New Zealand on Monday following their 44-16 thumping by the competition-leading New South Wales Waratahs on Sunday.
The 28-year-old All Black was not expected to be discharged from hospital until Tuesday, the Highlanders said in a statement.
The loss of Smith, capped 29 times for New Zealand, would be a big blow for the Highlanders, who can snatch the New Zealand conference from the Crusaders' grasp if they score four or more tries in a victory by more than seven points, while denying their opponents a bonus point.
A loss in Christchurch, however, could tip the fourth-placed Highlanders out of the top six and playoffs contention if other results go against them in this weekend's final round of the regular season.
The Crusaders, who qualified for the playoffs with a win over the Blues over the weekend, will face the Highlanders without All Blacks captain Richie McCaw, who missed their last two matches after suffering a broken rib in the test series against England last month.