RUGBY/Tour to Argentina assessment: Gerry Thornleyon how Eddie O'Sullivan's task now is to get the right split between backs and forwards for the World Cup

A 2-0 Test series defeat to Argentina may not have much significance come another momentous, make-or-break World Cup meeting in Parc des Princes on September 30th. Nonetheless, it will have served to dilute the heady optimism of last autumn. Remember? When Ireland were seemingly set to win the Grand Slam and then the World Cup?

Reality has dawned a little more brightly. The failure to beat frontline opposition from the Southern Hemisphere on a summer tour dates back to 1979 and acts as a reminder that Ireland will be competing in a World Cup pool containing three of the world's top six or seven sides. In a straw poll on Ireland's possible finishing position in this group on Saturday night, only one of our table plumped for Ireland to finish first - five went for second place, and three for third.

It's salient to note again that 13 Argentinians were unavailable because of the French Championship semi-finals and that a fully-fledged, professional Ireland squad faced a home team with six amateurs in their starting line-up. Looked at another way, even if Charlie McCreevy's tax rebate and the IRFU's professional structures weren't in place, would 13 Ireland players make the top four French clubs?

It's also pertinent to remind ourselves that in addition to playing the hosts in the Coupe de Monde, the majority of the Pumas team to play Ireland will be enjoying the familiarity of their adopted home.

In a general sense, the forward play held up reasonably well, especially the set-pieces, and while the counter-rucking and continuity were reasonably good, Ireland wouldn't be the first side to struggle in producing the quick ball their gifted game-breakers thrive on.

That, more than anything, will be the crux of the task facing Ireland in Paris on September 30th, for without it, the mediocrity of the back play over the last two Saturdays was the most disappointing feature of the tour. Brian Carney was the only Irish try scorer in the two Tests, and that was from an interception, admittedly as O'Sullivan experimented like never before and perhaps kept his powder dry.

The Ireland coach intimated strongly that the first of two warm-up Tests - against Scotland on August 11th - will be used to finalise one or two places in the World Cup squad, so all is not decided yet.

In naming his 30-man squad, O'Sullivan's biggest decision will be whether to opt for a 16-14 or 17-13 split between forwards and backs, but in saying that, he did bring an extra backrow on this tour, so he appears to be thinking of a 16-14 split. In effect this would mean five backrowers, rather than six, to accommodate an additional outside back.

A 17-13 split would accommodate six backrowers, where arguably the toll is greater, but five would leave little room for rotation. Four years ago, O'Sullivan was obliged to start all five backrowers, whereas he started the same three-quarter line and fullback in all four pool games before making one enforced change - John Kelly for Denis Hickie - in the quarter-final defeat to France. As with Frankie Sheahan, Gary Longwell and Neil Doak, Anthony Horgan and Paddy Wallace were surplus to requirements.

Bringing half a dozen backrowers would also be playing to Ireland's strengths, allowing O'Sullivan to bring another specialised openside and enable him to rotate the six fully in the opening matches against Namibia and Georgia. Admittedly bearing in mind the need to bring three hookers and three scrumhalves, a 17-13 split would limit O'Sullivan to having just three backs covering the back five. Even so it might be preferable to play a couple of the backs in every game than, say, David Wallace doing so.

Selecting just five backrowers might highlight the greater versatility of Stephen Ferris, and could mean that both Keith Gleeson and Shane Jennings, and even more unluckily Jamie Heaslip, might miss out. Intriguingly, O'Sullivan said he'd like to have seen more of Ferris, suggesting that perhaps this is one of the areas he will have another look at in Murrayfield on August 11th.

Recalling how the then 21-year-old Bob Casey made his debut in the 1999 World Cup, and was plunged into the last quarter of the Lens defeat in only his second cap, ideally the World Cup is not a place for relative international greenhorns, but Ferris again showed his enormous potential last Saturday.

Alan Quinlan certainly put forward his case in Buenos Aires last Saturday, clearing out rucks, reaffirming his lineout ability, making his tackles, carrying and generally being a pest. No matter whether O'Sullivan brings five or six forwards, Quinlan would probably have to usurp Neil Best to travel, and while he is arguably a better footballer, Best is the younger wrecking ball and his face appears to fit more.

The argument for a fourth lock who can cover the backrow would be heightened by a 16-14 split, and hence help Mick O'Driscoll aboard the flight to Bordeaux, though even his injury-curtailed performances in Rome and Buenos Aires raised questions about his durability as well as his form.

Leo Cullen is more experienced, and Trevor Hogan is arguably the most in form, yet O'Driscoll's face seems to fit more.

Gavin Duffy's versatility over the last two Saturdays, as a fullback and inside centre, made him the net winner of the tour. You would hope that Geordan Murphy's versatility alone, not to mention his potential brilliance, will help him atone for cruelly missing out four years ago. As he can also play wing, witness his barnstorming display in the win over South Africa, and centre, and is one of the coach's favourites, Andrew Trimble should also go.

In a 17-13 split that would be that, but if there's an additional place for an outside back, Tommy Bowe's form for Ulster and past experience ought to have him highest in the pecking order. However, Brian Carney looks to have done more than either him or Robert Kearney. For Kieran Lewis and Barry Murphy, this was an opportunity missed, whereas curiously, despite looking sharp in his late cameo, Luke Fitzgerald wasn't given much of a chance.

Those three missed penalties put paid to any hopes Jeremy Staunton had of edging out Paddy Wallace. In mitigation, no position requires a greater investment in time than outhalf, and through no fault of his own, Staunton's preparation with Ireland equated to a crash course. A nagging suspicion remains that the Irish coach might yet sound out David Humphreys, still the second best Irish number 10 around, though there is no sign of any white smoke here.