Coach Mike Hesson is adamant they have few choices. New Zealand have won only one match against Sri Lanka in their last 11 completed 50-over matches from 2007.
The Black Caps believe they have done enough to overcome their jitters against the turning ball, as seen in the West Indies, India and Sri Lanka last year.
Hesson says due diligence has been done: "We know most of them. Few have played against [off-spinner] Senanayake but Brendon [McCullum] played with him at Kolkata in the IPL.
"They've made four of the last six ICC finals. They have aggressive batsmen at the top of the order who combine with experience in the middle. Their spin bowling takes wickets and they've got the [Lasith] Malinga factor when he gets it right.
"You could conceivably be facing up to 35 overs of spin. We need to be proactive."
Nathan McCullum looks likely to play his 50th ODI for New Zealand, whether Daniel Vettori returns to fitness or not. On a wicket which seemed to hold up slightly when India beat South Africa, McCullum would be useful.
"It aids bowlers with a decent change of pace and slower bowlers," said Hesson. "I imagine Sri Lanka will stack their line-up with them."
McCullum's had past success against Sri Lanka, including being man of the match in New Zealand's only win against them in a World Cup or World T20 match over the last 21 years (the 2010 T20 in Guyana). He was also one of two in the current squad who joined a T20 team - the Ruhuna Royals - in the inaugural Sri Lankan Premier League last year. The other was Kyle Mills.
McCullum trained with the side, which included Sri Lankan paceman Malinga, but did not play in the tournament. Instead he rushed home to be with his wife for the birth of their child. He also knows about bowling to batting greats Mahela Jayawardene and Kumar Sangakkara, having previously dismissed them in ODIs and T20Is.
"We've missed Dan [Vettori] over the last couple of years so I've had a bigger role," McCullum says. "I have also done a lot of bowling in the nets in India during the IPL even though I didn't play with the Sunrisers Hyderabad [where Sangakkara led the side].
"I reckon we have an edge after a hard-fought one-day series against England, rather than warm-up games. The intent, attitude and fight sometimes doesn't come out otherwise."
Hesson pointed to the death bowling as the main area requiring improvement after what he described as a "blip" in the final one-day loss to England at Nottingham.
"The first 46 overs in the field, we were exceptional [England scored 76 runs off the last four overs]. It's probably the first time we've been put under pressure at the death for the last seven or eight one-dayers. It exposed our execution which is probably not a bad thing."