McCullum, as an opener, averages 45.13, nine runs better than his overall record over 61 tests.
Nicol is on debut tomorrow and it may be the selectors preferred to leave him where he's played the bulk of his cricket in the latter stages of his career. However he was a capable middle order batsman through the earlier part of his career with Auckland.
"Martin and Rob have shown a good partnership and Brendon is happy to open or bat at No 3," returning captain Ross Taylor said.
''Rob opens for Canterbury and that was probably the main reason. They've been batting there for so long so why change it?"
Taylor won't be ordering Nicol to change a reasonably free-wheeling limited-overs attitude either.
''Just because it's your debut you don't need to change anything," he said.
''A few years ago Rob Nicol would have scored 50 off 200 balls opening the batting. ''The last couple of years he's changed his game and he's been rewarded for scoring a lot of runs. I don't expect Rob to change the way he plays; go out and see off the new ball and play his shots."
One of the threats Nicol and Guptill will face will come from relatively unknown fast-medium Vernon Philander.
Whereas Dale Steyn and Morne Morkel offer pace and bounce, Philander has taken 30 wickets in just four tests primarily with movement off the pitch and accuracy.
''He's had an unbelievable start to his test career," South African captain Graeme Smith said.
''He's a very different style to the rest of our attack. He asks a lot of questions, gets the ball in the right area more often that not and most often on flat wickets he still gets the ball to talk quite a lot.
''He brings a lot of consistency to our attack and I think he's been a real asset to the pace of Dale and Morne, and really gives us a good balance to our attack."
And Smith reckons the Soluth African mentality has changed since the 2004 tour here when he had his hands full in the captaincy battle with experienced New Zealand leader Stephen Fleming.
''They (New Zealand) had a really experienced team back then. We were a little bit wet behind the ears.
''But we've got a very exciting legspinner (Imran Tahir) now and more pace.
''I think we're far more attacking mindset-orientated now. We used to tour with the mindset of seeing how well we could do.
''Now we tour with the mindset of 'we've come here to win'.
