Illness could force Black Caps coach Mike Hesson into finally making changes to his world cup playing XI.
The Black Caps' final pool match is against Bangladesh in Hamilton on Friday.
Coach Mike Hesson wasn't forthcoming with details as to who is sick but he did confirm they also have an injury concern in fast bowler Adam Milne, who suffered a shoulder niggle in the win over Afghanistan in Napier.
A team spokesman says it seems a couple of players have come down with a virus.
Hesson has steadfastly stuck with the same playing XI throughtout the side's five-match winning run at the tournament and confirmed his commitment to keeping the same lineup if everyone was fit.
After Friday's game their next match is a quarter-final in Wellington against either the West Indies, Pakistan or Ireland on Saturday week.