Blackcaps v Australia: Todd Astle says NZ taking extra precautions due to virus sweeping through camp

New Zealand players stopped high-fiving a sick teammate to prevent a virus spreading, as coaching staff prepared to field in case of emergency during another dramatic day at the Sydney Cricket Ground (SCG).

The Blackcaps' tour from hell took another twist on day two of the third test, with scans showing pace bowler Matt Henry had broken his thumb; recalled batsman Jeet Raval then joined the ever-growing sick bay.

Henry has bowled through the pain barrier after trying stop a Joe Burns drive on day one because the blow affected his non-bowling hand.

However, the handy tailender may not bat if Australia continue to dominate a one-sided three-match series.

Raval was the latest Kiwi to succumb to a flu-like virus, joining skipper Kane Williamson, batsman Henry Nicholls and spinner Mitchell Santner who were all ruled out before Friday's toss.

Raval was resting in the dressing room when the Blackcaps took to the field on Saturday and missed the first hour of play.

He was feeling healthier by stumps on Saturday, but worryingly the bug has so far affected players for days rather than hours.

"You have to be very diligent with things like hand sanitiser and being round food and people who aren't feeling great," New Zealand spinner Todd Astle said.

"You have to have certain measures in place. We've been smart about it and in terms of high-fives it was different with Jeet - [it was tap] elbows or just a gesture.

"We don't want anyone else going down."

Raval's illness left just 12 healthy players in the touring squad for the early stages on Saturday.

Batting coach Peter Fulton, a former test opener, wore whites as a precaution in case he was required as a substitute fielder.

Spinner Will Somerville is also understood to be carrying a hand injury, with the webbing between his ring and middle finger split on his non-bowling hand.

The issues further complicate a horror few days for the New Zealanders, who were gutsy in their reply to Australia's 454, reaching the close on 63/0.

Premier seam bowler Trent Boult returned home earlier this week after he had a hand was broken by a Mitchell Starc delivery in the Boxing Day test before Australia took an unassailable 2-0 lead.

Injuries and illness prompted debutant Glenn Phillips to be flown in as a last- minute inclusion for Sydney, while Raval, Astle and Somerville were all joined a depleted XI.

Henry replaced veteran Tim Southee, with the Blackcaps believing he had more to offer than weary opening paceman, who has endured a busy workload.