Northland's Tim Southee has been admitted to hospital with dehydration and Rob Nicol is also too ill to travel to Kandy ahead of New Zealand's first Twenty20 World Cup match against Bangladesh on Friday.
Southee, who New Zealand Cricket said was displaying symptoms associated with gastroenteritis, has been admitted to a Colombo hospital. He is not thought to be in a serious condition.
Daniel Vettori, who like Southee was ruled out of Monday's warm-up defeat to South Africa in Colombo due to illness, thought to be food poisoning, has improved and has travelled with the team.
Nicol played in the South Africa match but is now also ill. New Zealand's stocks were so low that bowling coach Damien Wright was forced to field for the Black Caps.
"We had a few illnesses leading into the match, only having 11 there, but the whole squad's had a game so far in the last couple of weeks, so we're looking forward to the start of the World Cup," captain Ross Taylor said.