Brownlie is 32, has been around the game a long time, and knows the score.
"For me, it's games I wouldn't have played if Guppy had been fit," he said of New Zealand's last two ODIs, when he's contributed an ODI career-best 63 against Australia, then 31 last Sunday, also at Seddon Park in Hamilton against South Africa.
"I've got nothing to lose. I love playing for New Zealand. That will never change. I want to go out hopefully make good contributions for the team and be part of some wins."
Brownlie's batting average from his 12 ODIs is an ordinary 29.7 but you suspect he's a better batsman now than he was in his earlier stints in the one-day side.
There's also a quandary building for New Zealand with their top order.
Left-hander Tom Latham's not in good nick but is sharing wicketkeeper duties with the specialist Luke Ronchi. There's no guarantee, after a run of 22, 4, 7, 0, 0 since hitting a century against Bangladesh on Boxing Day, Latham will hold his spot if more failures follow.
A Guptill-Brownlie axis at the top with Ronchi taking the gloves is quite feasible.
South Africa will chase a record-setting 13th ODI win today. They've not presented any surprises to New Zealand, who have been reminded why they are the new No1 team in 50-over cricket.
"When someone goes out they seem to replace him with someone just as good. Their depth if obviously strong. Guys keep standing up and becoming world class cricketers," Brownlie said.
Hard-hitting left-hander David Miller, recovering from an injured little finger, might not start. If not, Wellington beckons.
Lockie Ferguson, fresh from bagging an Indian Premier League contract on Monday night, is a good chance to play for New Zealand, and if so that would most likely be at the expense of legspinner Ish Sodhi.
It depends on how long the selectors will give Jimmy Neesham to make a significant contribution at No6. He was exposed by Australia's fast bowlers and his seamers have also looked very hittable recently and that presents risk against high calibre batsmen led by ODI skipper, and batting boss, AB de Villiers.
The other boss was in Christchurch last night, Bruce Springsteen thrilling a sold out crowd.
A full house is expected at Hagley Oval today as well. New Zealand need to deliver or, at 0-2, the ODI rubber will just about be out of their grasp.
NZ v South Africa
Second ODI, Hagley Oval, 11am today
New Zealand: (from) Kane Williamson (c), Dean Brownlie, Tom Latham, Ross Taylor, Neil Broom, Jimmy Neesham, Colin de Grandhomme, Mitchell Santner, Luke Ronchi, Tim Southee, Ish Sodhi, Lockie Ferguson, Matt Henry, Trent Boult.
South Africa: (from) AB de Villiers (c), Quinton de Kock, Hashim Amla, Faf du Plessis, JP Duminy, David Miller, Farhaan Behardien, Andile Phehlukwayo, Chris Morris, Kagiso Rabada, Imran Tahir, Tabraiz Shamsi, Dane Paterson, Dwayne Pretorius.