Come again? So a win perhaps?
"If he bats an hour or two we could be a long way to winning the match," Latham said of McCullum.
Australian spinner Nathan Lyon would still rather be in his team's shoes.
"We've got to come out and bowl well. We bowl well, we win this test match," he said.
The potential challenge of a fired-up McCullum appeals.
"He's dangerous but I love challenges, so bring it on."
If the weather intervenes it may count as fortunate, but that happens, you take the breaks, be thankful and move on.
If it goes wrong today, New Zealand can have no complaints. They have been taken apart for the bulk of this match, Kane Williamson the one shining beacon in the gloom of the Gabba.
New Zealand do have recent form " in the United Arab Emirates and England " for rebounding hard to square series. It's certainly an admirable quality and one of the reasons why it would be premature to write them out of this series.
Also it's worth remembering captain McCullum and the next two batsmen in, Jimmy Neesham and BJ Watling, were part of New Zealand's stunning survival against India in Wellington last year. So they have previous in this department.
When the final day starts, New Zealand will be 142 for three, needing a further 362 for victory for what would be the greatest fourth innings chase in test history. Despite Latham's upbeat view, best park those thoughts though.
New Zealand have three of the six highest fourth innings totals in tests " headed by the 451 against England in the Nathan Astle double century match at Christchurch in 2002 " but all three matches were lost.
They need to be smart, pick the moments to be offensive on a pitch which is still good for batting, albeit taking more spin for Lyon, and they will give themselves some hope.
Yesterday was given over to hunkering down and for a time boring was good. Don't tell the spruikers demanding ball-by-ball exhilaration in the interests of keeping the game strong in the sports entertainment business, but there is more than one way to make this game fascinating.
A couple of weather breaks yesterday didn't hurt. Whoever was in charge of the rain dance in the New Zealand dressing room, give that man an umbrella. Every bit of time off the field helped New Zealand's cause.
But the loss of Williamson was a heavy blow. He had been in charge, seemingly continuing on where he'd left off in his terrific first innings 140, in reaching 59 before going lbw to Lyon, his referral rejected.
It was a tight decision " ball tracker showing it would have clipped the top of the bails, and thus supporting umpire Richard Illingworth's decision " but by no stretch a wrong one. Just tough.
"He's a world class batter and seems on top of his game at the moment.
"To get his wicket was pretty big for us," Lyon said.
It was a break New Zealand could certainly have done without.