Neesham set to open against SA
Neesham, who averages 19.50 in ODIs with all his nine innings coming at No. 6 or lower, was tested as an opener in the T20 series in West Indies in July, when he made 18 runs in two innings. McCullum, however, believed Neesham had something "special" about him and backed the allrounder to become a "destructive player" at the top.
"He [Neesham] will get an opportunity tomorrow at the top of the order. He spent about three hours batting in the nets so he should be ready," McCullum said. "He's an exciting player and it's not an easy role that, especially against a team like South Africa with their quick bowling options.
"I think he's got something a little bit special and with Kane (Williamson) under a bit of a cloud with his bowling we still need to create a bowling option in the top five. Until you put people in those positions you're not 100% sure how they're going to respond.
"For me it's about how he goes about constructing his innings. If we can get that destructive kind of player at the top, playing with some freedom, then that goes a long way in assisting us with the rest of our line-up."
McCullum's confidence in Neesham was reiterated by New Zealand coach Mike Hesson, who was keen on having a bowling option in their top three.
''There is no doubt that South Africa have a fine seam bowling attack but James is a quality player and he's looking forward to that opportunity,'' Hesson told the Dominion Post. "He's been preparing for the last few weeks knowing that's his role. We certainly haven't been chucking him in [the nets] against the old ball.''
McCullum said in the absence of the injured Williamson and Ross Taylor, New Zealand's top five would be Neesham and Guptill, followed by Dean Brownlie, McCullum at No.4, and Tom Latham. Brownlie has not played an ODI since July 2012, but he battled against a South African attack comprising Dale Steyn, Morne Morkel and Vernon Philander to score a century in the Cape Town Test last year, albeit in a losing cause. He also collected hundreds for New Zealand A against England Lions, and in a tour game against Kent in August.
"If he's not at full capacity then he won't play the first one, but he'll certainly be available to play two and three and should be firing for it by then," Hesson told NZ Herald. "He's strong and fit and he recovers quickly. So this time of year it's not an opportunity to push guys too hard too soon."