The concept wasn't without justification. Guptill had suffered a form blip.
His nadir came with a duck against Sri Lanka in Wellington on January 29. He has since built a strike rate of 100.06 and averaged 64.95 from 27 innings. More importantly, New Zealand has secured 18 wins, eight losses and one no result from those matches.
Any suggestion of his removal is preposterous now.
Guptill has excelled to a point where, in 2015, he made the most runs by any player in the world (1489 at an average of 55.14 and strike rate of 97).
To give that perspective, McCullum's career ODI strike rate is 96; Guptill's is 85 and escalating.
At 29, and with a 124-ODI pedigree, Guptill's credibility is established.
Put another way, New Zealand has not lost an ODI in which Guptill has scored any of his 10 centuries. Five of those came in his last 20 innings, including the New Zealand record 237 not out against the West Indies in the World Cup quarter-final. Of those 20 innings, he has scored less than 22 just four times.
Such consistent contributions come at a welcome time, as Kane Williamson makes his expected transition into the captaincy.
Cricket leadership comes in a variety of forms beyond tactics and strategy. Guptill, at least publicly, strikes as a man of pathological shyness, but he is providing direction with his gluttony for runs.
When the original Guptill criticism emerged, coach Mike Hesson spoke of not wanting to create a "headmaster's office" culture for anyone with brittle form.
Guptill has repaid that faith. The sight of his front foot easing down the wicket to draw customary seven-irons over long on is reassuring for fans.
He will seal the McCullum vacuum and leave his own indelible legacy if his appetite for runs remains.
