All week the host nation management have spoken in glowing terms about the experience of the Irish, their good recent record, the presence in the squad of world class players while pointing to the rash of injuries that have beset their own squad.
All that aside the task facing O'Sullivan's side is an awesome one.
It has been a long season and there is also the factor of playing at altitude against a side who are desperate to establish - or re-establish - themselves in the top echelon.
O'Sullivan agrees that he has basically all the players he wants on this trip and he makes no secret of the fact that he believes that if everything goes to plan his side can create history.
And on the evidence of what has gone before, no-one can rubbish that ambition.
This is a good Irish outfit, loaded with experience and with some exceptional players in key positions. The one factor that may seriously damage their hopes is in fact the rigours of playing at 5,000 feet above sea-level. To combat that, they've adopted the Super 12 style of, 'arrive late' and it is to be hoped that O'Sullivan has got this right.
The Irish can expect the home side - roared on by a partisan crowd - to come at them right from flagfall but they've been in this type of scenario before and if they can withstand the early onslaught, experience, battle toughness and a little bit of D'Arcy/Murphy/O'Driscoll magic can see them record a famous victory.
Ireland:Girvan Dempsey;Shane Horgan, Gordon D'Arcy, Brian O'Driscoll, Geordan Murphy;Ronan O'Gara, Peter Stringer; Anthony Foley, David Wallace, Simon Easterby; Paul O'Connell, Malcolm O'Kelly; John Hayes, Shane Byrne, Reggie Corrigan.Replacements: Frankie Sheahan, Marcus Horan, Donncha O'Callaghan, Alan Quinlan, Guy Easterby, David Humphreys, Kevin Maggs.
South Africa: Gaffie du Toit;Breyton Paulse, Marius JJoubert, Wayne Julies, Henno Mentz; Jaco van der Westhuyzen, Fourie du Preez; Jacques Cronje, Pedrie Wannenburg, Schalk Burger; Victor Matfield, Bakkies Botha, Eddie Andrews, John Smit (captain), Os du Randt.Replacements: Hanyani Shimange, CJ van der Linde, Quinton Davids, Gerrie Britz, Bolla Conradie, Jacque Fourie, Brent Russell.
Referee: Tony Spreadbury (England) Touch Judges: Joel Jutge (France) and Giulio de Santis (Italy) Television Match Official: Nigel Owens (Wales)