It seems to be working. The opener hasn't had a higher score in 10 ODI innings since his 111 at the same venue a year ago.
Such problems haven't dogged him domestically. He's scored two centuries and a 55 in his last four Ford Trophy innings.
However, like Hamish Rutherford in the test format, the selectors have persevered. Guptill has the added security of being in the World Cup squad and that guarantees him a maximum of six more ODI innings and a couple of warm-ups before the tournament starts.
It's hoped Guptill can deliver more 2013 Southampton moments of zen, when he made New Zealand's highest one-day score - 189 not out - against England and waved his bat like a magic wand.
"I always enjoy being in front of my home crowd at Eden Park," he said. "It's generally a good batting wicket and [the batsmen] love the short boundaries."
Guptill's average of 76.16 in nine innings at the venue is more than double a career average of 37.86 in 90 innings. He brought up 3000 ODI runs yesterday, becoming the fastest New Zealander to complete the feat.
He acknowledged his pre-match practice but said he didn't indulge too much: "[I didn't have] too many. My feet have been moving quite well this year and I've been feeling in great nick, so it was nice to spend some time out there.
"I just tried to go out and bat. If I got a bad ball, I tried to put it away. It was nice to find a few gaps rather than fielders and get a few boundaries."
Unfortunately, the weather did its best to disrupt his rhythm, in addition to the efforts of the Sri Lankan bowlers who had him chopping two French cuts and a return chip early in his innings.
Guptill's resurrection may have been helped, in a peculiar way, by the premature dismissal of Brendon McCullum for 28 off 22 balls. It meant he was not subject to peer pressure to take advantage of the short boundaries like his skipper.
Guptill said McCullum's presence doesn't affect him adversely. "Brendon plays the way he does and it often comes off. It's spectacular to watch when you're out in the middle.
McCullum fell to a steepling catch from Nuwan Kulasekara off Angelo Mathews, much to the chagrin of dozens of orange T-shirted fans who swarmed to prime posts 20m beyond long-on and long-off.
Mathews also bowled Tom Latham for 42 and had Ross Taylor lbw for three to finish with three for 21 from 6.5 overs.
The groundsmen ended up playing the biggest cameos. They were like a land-lubbing crew of America's Cup sailors wrestling the scrim and plastic covers into position as the waves of misty rain swept in.
The seven-match series remains level at 1-1 with the fourth game in Nelson on Tuesday.
