Now is the time for the likes of captain Angelo Mathews, veteran opener Tillakaratne Dilshan, Lahiru Thirimanne, Dinesh Chandimal and spirited young quicks Dushmantha Chameera and Suranga Lakmal to stand up.
"There's a lot of experience in the team, unlike the test team where there were guys who had just played two or three tests matches," Jayaratne said.
"A lot of these guys have played 50-100 one-day matches. We have to put this behind us, come back and put up a good performance."
Sri Lanka have one player who has caught the eye on this tour, left-handed allrounder Milinda Siriwardana, who looked capable in the two tests and made an impressive 66, standing alone among the top order wreckage as Adam Milne and Matt Henry reduced Sri Lanka to 27 for five.
"He's a bit of a late developer," Jayaratne said of the 29-year-old Siriwardana.
"He only started getting consistent runs over the last season or two. There's something about him, yes."
Nuwan Kulasekara got to 58 with the bat, but he's in the side for his bowling, which was ordinary.
Then again, there wasn't much any of the tourists' attack could do about the McCullum-Guptill onslaught.
"It's bloody nice having him on our team," Henry quipped when asked if he had some sympathy for the Sri Lankan attack trying to contain McCullum.
Today is likely to see Henry Nicholls given a second appearance. The Cantabrian hit the winning runs on Saturday in an unbeaten 23 off 21 balls.
If Nicholls, a compact lefthander who is in good form, can take his opportunity, he will also enhance his chances of graduating to the test team later in the year once McCullum has gone.
With Boult and Southee to return at some point shortly, there is expectation on Milne, Henry, Mitch McClenaghan and Doug Bracewell to deliver.
Henry took his chance superbly on Saturday and Milne was slippery, while Bracewell kept up a good recent run of form.
One of that quartet will rest today if the selectors decide they want to see legspinner Ish Sodhi in action.
Then again, the collective performance of the speed quartet might be enough to suggest they be sent out again today.
Ticket sales for the game are around 5500 for the 8500 capacity Hagley Oval.
New Zealand are chasing a 12th successive ODI victory today.
New Zealand v Sri Lanka
Hagley Oval, Christchurch, 11am today
New Zealand: (from) Brendon McCullum (c), Martin Guptill, Kane Williamson, Ross Taylor, George Worker, Henry Nicholls, Luke Ronchi, Mitchell Santner, Doug Bracewell, Ish Sodhi, Adam Milne, Mitchell McClenaghan, Matt Henry.
Sri Lanka: (from) Angelo Mathews (c), Tillakaratne Dilshan, Lahiru Thirimanne, Dinesh Chandimal, Milinda Siriwardana, Chamara Kapugedera, Kithuruwan Vithanage, Danushka Gunathilaka, Thisara Perera, Suranga Lakmal, Ajantha Mendis, Sachithra Senanayake, Dushmantha Chameera, Jeffrey Vandersay, Nuwan Pradeep, Nuwan Kulasekara.