Ulster flanker Neil Best has been named in Ireland's team for Saturday's first Test against New Zealand in Hamilton.
Best will win his third cap against the All Blacks on Saturday
Best, who replaces the injured Simon Easterby, will win his third cap and comes into a side showing two changes to the team that won the Triple Crown.
The other change sees Munster lock Donncha O'Callaghan replace Malcolm O'Kelly, who has a groin injury.
Uncapped Ulster duo Bryan Young and Isaac Boss are named as the replacement prop and scrum-half respectively.
Kiwi-born Boss, whose grandmother came from Glenarm in Co Antrim, returns to his former 'home' patch at the Waikato Stadium were he initially made a name for himself.
"You don't mess around and experiment against teams like New Zealand and Australia," O'Sullivan said.
"We're here to try and get a job done and put the best team on the field we can in each game."
All Blacks coach Graham Henry changed his side from game to game on their 'grand slam' tour of Britain and Ireland last November.
But O'Sullivan admits he does not have the luxury of adopting the same philosophy.
The most important thing in Test rugby is to win
"Graham has got that sort of strength in depth at the moment where he can do that and I think most coaches in world rugby would like to have that latitude," he said.
"What he's got to do is make sure he wins all his games and when you've got a schedule like New Zealand have you maybe have to work your squad a bit.
"I would like to do the same sometimes but we maybe don't have that latitude and the most important thing in Test rugby is to win."
Henry has lost lock Ali Williams for both Tests - Saturday's first match at the Waikato Stadium and the second at Auckland's Eden Park a week later.
The Blues second-rower suffered an ankle injury in training and has been replaced in the All Blacks side by experienced Crusaders lock Chris Jack - originally pencilled in for a rest.
Rawlinson has rejected approaches to return to South Africa
North Harbour lock Greg Rawlinson comes into the second row alongside Jack for his Test debut, after the Durban-born forward qualified for New Zealand residency.
Rawlinson has rejected approaches from South Africa coach Jake White to return home and play for his country of birth.
Prop Clarke Dermody will also make his Test debut in place of Tony Woodcock, who is still out with a calf injury, while Marty Holah starts at blind-side flanker.
Flanker Jerome Kaino, fly-half David Hill and wing Scott Hamilton could also make their Test debuts from the bench.
Prop Neemia Tialata has recovered from the knee injury he picked up in the Super 14 final and is among the substitutes.
"We are pleased for the new All Blacks," said Henry. "We are pleased to have more players of international calibre available to the team.
"We want depth to be a strength for New Zealand rugby."
New Zealand: Muliaina; Howlett, Nonu, Mauger, Rokocoko; McAlister, Kelleher; Dermody, Mealamu, Hayman; Jack, Rawlinson, Holah, McCaw (captain), So'oialo.
Replacements: Hamilton, Hill, Cowan, Kaino, Flavell, Tialata, Oliver.
Ireland: G Murphy (Leicester); Horgan (Leinster), B O'Driscoll (Leinster, captain), D'Arcy (Leinster), Trimble (Ulster); O'Gara (Munster), Stringer (Munster); Horan (Munster), Flannery (Munster), Hayes (Munster); O'Callaghan (Munster), O'Connell (Munster); N Best (Ulster), Wallace (Munster), Leamy (Munster).
Replacements: R Best (Ulster), Young (Ulster), M O'Driscoll (Munster), Gleeson (Leinster), Boss (Ulster), Hickie (Leinster), Dempsey (Leinster).
Referee: Stuart Dickinson (Australia).