Tim Southee's illness means New Zealand will wait until Friday morning before announcing their starting XI for the second Test against England at Old Trafford.
The teenager only returned to training on Thursday after being struck down with 'flu during the drawn first Test at Lord's, where he bowled 16 wicketless overs.
The tourists have retained the same 12-man squad as Lord's. That includes medium pacer Iain O'Brien, who is poised to step into the starting line-up should Southee be ruled out, meaning there is again no place for off-spinner Jeetan Patel.
Black Caps skipper Daniel Vettori told a news conference: "He (Southee) hasn't trained the last couple of days. He's been down with a virus but he seems to be ready to go today.
"We'll sit back and see how he goes and how he comes through it then we will make a decision on our final XI, probably tonight."
Vettori sounded slightly concerned about his side's ability to adapt to what is expected to be a fast, bouncy pitch at Old Trafford.
"We don't come across too many fast, bouncy wickets and probably around the world these days you don't come across too many," Vettori admitted.
"Even Perth has lost a little bit of its reputation so it will be a new experience for us.
"But I guess for a lot of our new guys every Test match situation is a new experience, so this is just a new one to try to adapt to.
"I played here in '99 and probably would have called it a low, slow turner, so it is going to be completely different.
"Just like any situation going around the world, the team that adapts to it best is going to get the result on the day.
"Sometimes bowlers get carried away with extra pace and bounce so it is almost they how have to adapt more than the batsmen.
"That is the key thing we will be stressing now: you can get excited about it but the same lengths on a bouncy wicket are the same lengths on what we played on at Lord's, so we don't want to change too much."
England have named an unchanged team for the match that gets under way on Friday.
New Zealand squad: Jamie How, Aaron Redmond, James Marshall, Ross Taylor, Brendon McCullum (wkt), Daniel Flynn, Jacob Oram, Daniel Vettori (capt), Kyle Mills, Tim Southee, Chris Martin, Iain O'Brien