"We are setting out our stall and getting fellas on the same page. It's not about bashing or boxing at this time of the year. We want to get them focussed and with a clear mind.
"It's not a long tour and we have players being rested and that gives fellas a great opportunity to throw down a marker for the World Cup," he added.
"Unlike the last World Cup, our time frame is a lot tighter. We will have only one warm-up game before we must name our squad. The last time we had three warm-up games before naming the squad.
"This tour is the real deal for a lot of guys to put their hand up for a World Cup place. For that reason it is a very important tour and the players know that and it's not about intensity in training. It is about holding them back.
"It is a pressure situation for some of the players but that is what rugby is all about. It's good that we are in that situation, and that is the strategy we've adopted this year."
Asked about resting his first choice players from the Six Nations, O'Sullivan said: "I always had it in my mind to rest as many players as possible and I'm glad we had that opportunity - it opens the door for those travelling (to Argentina). There is a fair bit of pressure on them and they have a lot to play for. That is a great way to go on tour.
"We are not going out just to fulfill the fixtures. We are going out to win two Test games. It will be a tall order. It's never easy to win out there but it is a good target to have."
So what sort of selection strategy will the Irish management adopt on Argentinian soil? "I would like to give as many players as I can a run," explained O'Sullivan. "If you look at the structure of the squad we have 17 forwards and 13 backs which is unusual because we normally opt for 16 forwards and 14 backs. I need to see as many of the back rows as possible. I think you will see quite a few changes in the team from week to week.
"The players involved in the Heineken Cup final will arrive next Tuesday which gives them a short build-up for the first Test on Saturday week, so the first Test will probably involved those who are in camp here with us in Limerick.
"We will make as many changes as possible but that doesn't mean that all the players will get a chance to play. The tough part is that guys may only get one shot at earning a World Cup place, and that is especially true of the back row."
O'Sullivan is aware that Argentina might not be able to field a full strength side as the French club championship is not over and certain players may not be released.
"Argentina have a pretty good squad and I don't expect any favours from them. They will see a bit of an opportunity for them in that we meet in the World Cup."
O'Sullivan also conceded that there might be some teething problems for his side in South America as some players may not have played in the same position together before.
"What I would like to see on the tour is a lot of hunger and aggression and guys putting themselves around and giving as good a performance as they can," said the Corkman.
Asked if it was premature to introduce former rugby league star Brian Carney to union's international stage, he replied: "I wouldn't do it unless I thought he was good enough. I would still be guarded about it but from what I have seen of him with Munster, I think he is a very good player and is a footballer who has played at the highest level and he has made the transition pretty flawlessly.
"He played on the wing in rugby league and does the same in union. It's probably the easiest transition to make. I believe he will acquit himself well and it is a challenge for him. The next step up is to Test level.
"It was great for Brian to play full-back for Munster recently but the Magners League is not international rugby and it would not be fair to him to throw him in at the deep end at full-back in Test rugby.
"This tour is not about any experimental tactics. We will keep it simple and hopefully we will be wiser at the end of it."