New Zealand will start strong favourites against a Sri Lankan team seriously undermanned.
It's not just that they have lost their two batting champions of the last decade and a half, Kumar Sangakkara and Mahela Jayawardene, but also their most experienced seamer, Dhammika Prasad, is gone with a back injury while wicketkeeper Kusal Perera's failed drug test had him heading home prematurely.
Their probable XI tomorrow will include an opener on debut (Udara Jayasundera), a batsman playing his second test (Kusal Mendis) and an allrounder (Milinda Sirawardana) playing his third.
They will be in conditions some way removed from Colombo and Galle, where they won their last series against the hapless West Indies in October.
So much depends on captain Angelo Mathews, an outstanding cricketer whose numbers suggest he thrives on the leadership, opener Dimuth Karunaratne - scorer of 152 at Christchurch last December - wicketkeeper-batsman Dinesh Chandimal, averaging 45, and the veteran spinner Rangana Herath, whose portly appearance belies fine figures and considerable craft.
Mathews admitted filling the middle order Grand Canyon-sized hole left by Sangakkara and Jayawardene has pre-occupied the batsmens' minds. They got 484 against the West Indies recently in Galle, which leads Mathews to suggest "it's just a mindset".
"No one is going to stay forever. People come and go but the players have to take responsibility, be positive and take opportunities. Tomorrow is the day to prove it."
If Sri Lanka are batting tomorrow it's likely they'll have lost the toss - and the reverse applies too.
The pitch is dark brown with a decent covering of grass, should help seamers on day one but history suggests it will die over the following four days.
New Zealand will decide between Mark Craig's off spin or Neil Wagner as a fourth seamer this morning. Listening to McCullum's words today, the wise money would be on bustling left armer Wagner missing out.
"You've got to make sure the team you're picking is for a full five days," he said.
McCullum confirmed Mitchell Santner will bat at No 6, as he looks to cement himself in the test team after an encouraging debut at Adelaide.
"I'm sure over the next couple of years we're going to see the guy develop into a world class allrounder," he said of the laidback lefthander.
Santner's emergence makes room for four specialist bowlers, and the spinoff from that is the choice of four seamers or three plus a frontline spinner, hence the Wagner/Craig decision.
New Zealand should win this series. There's plenty stacked in their favour. So a final word on Mathews.
He averages 51.43 over his 54 tests; that number jumps to 65.91 from his 23 matches in charge. His bowling figures are also significantly better when he's been skipper.
In a team seriously light on hard match experience, Mathews stands as arguably the most pivotal figure in the series on either side.