Indeed, the Munster captain has not played since Ireland's loss to Scotland in March, missing his province's Heineken Cup quarter-final and semi-final clashes and last weekend's Magners League semi-final showdown with Leinster.
O'Connell's enforced lay-off, which he said has been 'hugely frustrating', included a stay at the Bon Secours Hospital in Cork where he received intravenous antibiotics to combat an infection.
Confirming his 33-man touring party at a press conference in Dublin on Tuesday, Ireland coach Declan Kidney admitted that it is very much a 'wait and see' game with the big lock.
"When you're announcing the squad, four weeks before we play New Zealand and six weeks before we play Australia, a player of Paul's calibre...you don't write off until you actually have to," he said.
"With the nature of his injury, there's a chance he'll get back. We'll give him every chance to do that. We do have a contingency plan in place should he not be able to make it."
O'Connell's presence on tour could be vital as Ireland chase their first ever win over the All Blacks and try to overcome the Wallabies on Australian soil for the first time since 1979, when current team manager Paul McNaughton was part of the victorious Irish side.
Kidney added: "Paul was under treatment where they expected an improvement after about two weeks. We're just coming into that two-week period now. He's showing some signs of an improvement.
"Percentage wise, I wouldn't like to put a figure on it. The nature of the injury is that once he shows an improvement then that the improvement could be rapid enough. Only time will tell."
Ireland are definitely heading Down Under without the services of Luke Fitzgerald (knee), Stephen Ferris (cheekbone), Denis Leamy (knee), Donnacha Ryan (shoulder) and Leo Cullen (shoulder).
Coping with injuries is part and parcel of being an international coach and Kidney accepts that the absence of those aforementioned players creates chances for others to impress.
"South Africa and Australia, when we played them in November, had bangs and knocks and they didn't complain about it. We have no intention of complaining about injuries now," said the Corkman.
"That's also why we've been building up a squad, because if you don't have depth in your squad, you're going to be found out in the latter stages of competitions."
Kidney explained the balance required in selecting a squad for such a rigorous tour: "There's a lot of guys there that I would like to see playing. But when you're playing the number one and three ranked teams in the world, you need to get a balance of experience in your side.
"It's unfair if you throw fifteen new guys into your team, then they're not going to learn things in the way that they need to learn them, and it's going to set them back even more.
"We've tried to get that balance right between bringing through a few younger guys and at the same time, representing the green jersey properly in matches."
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