Alan Quinlan: Versatility to be crucial point of difference when Schmidt makes tight calls for Japan

One thing that has become blindingly obvious, however, is the blooding of so many international players over the past three years has made picking a World Cup squad incredibly difficult.

It is, of course, a great problem to have. About 50 players have realistic ambitions of travelling to Japan as it stands and while injuries will undoubtedly play a role in the meantime, there are probably no more than six or seven spots still up for grabs.

Dislodging the incumbents in an international team is always a daunting task, but when they have Grand Slam and Six Nations medals around their necks, there is even more ground to make up.g

Next year Joe Schmidt will have to disappoint quite a few quality players who have done little wrong in green.

Some delicate hair-splitting will be required with near 50/50 decisions looming in a number of areas, such as the half-backs, back-row and back-three.

When it comes to tournaments like the World Cup you have to plan - and we know Schmidt is not lacking in this department - for every eventuality.

You need to be covered if your first- and second-choice options in a position go down injured in the same week.

Being 6,000 miles away from base adds another logistical issue to the equation - three years ago you could call on a replacement and have them on the training field in a matter of hours. Not so in Japan.

That, ultimately, means that versatility may well be the key to securing the golden ticket for those who are currently on the fringes. John Cooney and Tadhg Beirne have just a handful of Ireland caps between them but I expect both to make the final cut.

Ireland will likely only travel with five half-backs, and Cooney's ability to cover fly-half and split the posts from the tee, as well as the superb form he has shown since making the move to the Kingspan, makes him a really valuable asset in a tournament scenario. As it stands, Johnny Sexton, Joey Carbery and Conor Murray are certain to travel if fit.

Kieran Marmion is also likely to be included having proved himself so ably in the absence of the Munster scrum-half before, so I suspect the Leinster duo of Luke McGrath and Ross Byrne will be left to watch on from home.

McGrath would be particularly unlucky to miss out as he is another who has consistently delivered in green when required.

The number of world-class back-row combinations at Ireland's disposal is staggering and probably best highlighted by some of the players I couldn't fit into my 31-man squad - Rhys Ruddock, Josh van der Flier and Jordi Murphy, to name just three.

Beirne's form in recent seasons and his ability to cover so many positions makes him very difficult to leave out, even though he only made his international debut three months ago. On the back of such an honour-laden campaign, Dan Leavy will take some shifting, and, if fit, the colossal Seán O'Brien has to take the other No 7 spot.

Peter O'Mahony and Beirne are my blindside flankers - Iain Henderson is obviously an option here too - with CJ Stander and Jack Conan covering No 8.

The quality of our back-row stocks does bring great comfort too. Injuries are so prevalent in those positions, so to have the likes of Ruddock, who has captained Ireland to great effect, and Van der Flier, our starting openside in Paris seven months ago, in reserve is probably the finest illustration of the depth that Schmidt has developed in this World Cup cycle.

Henderson, James Ryan and Devin Toner will be hard to overtake as our second-row options, although Ultan Dillane, Quinn Roux and the powerful Jean Kleyn, who will be Irish-qualified just weeks before the World Cup begins, will all have aspirations of making the touring party.

The two loosehead spots look sewn up by Cian Healy and Jack McGrath, and the tighthead side is ably covered by Tadhg Furlong (who is close to Sexton and Murray in the 'irreplaceable' category), Andrew Porter and John Ryan.

If Niall Scannell can stay fit he could well be Ireland's first-choice hooker this time next year. Rory Best won't give the spot up without a fight but the 26-year-old Munster hooker has the attributes to overtake the Ulster man who is 10 years his senior.

Seán Cronin will probably travel too, his impact off the bench is hard to ignore, even though Rob Herring's reputation has grown on the back of his efforts in the three Tests Down Under.

Garry Ringrose, Robbie Henshaw and Bundee Aki are all but guaranteed to travel if fit, even if Ireland's first-choice midfield combination is not set in stone. Ringrose and Henshaw also add to the squad's versatility with the ability to cover wing and full-back respectively.

Chris Farrell is in danger of becoming the forgotten man but assuming he makes a steady recovery from his knee injury I think he will make it to Japan.

He was in incredible form before his season was cruelly ended only days after being named man of the match on his Six Nations debut against Wales - he offers something a little bit different and Schmidt is clearly a fan.

In terms of back-three cover, you would imagine that Keith Earls, Jacob Stockdale, Rob Kearney and Jordan Larmour will be on the plane as it stands, with Andrew Conway getting the nod for the fifth spot at the moment. Darren Sweetnam, Adam Byrne and Fergus McFadden will be leading the charge of the chasing pack, with Will Addison another intriguing prospect who can cover a number of positions.

Kearney answered his critics time and again last year but with so much back-three talent coming through he could come under pressure again this season if he doesn't hit the same heights.

Ireland were unlucky with injuries three years ago but Schmidt's strategy has focused on building a deep squad that can remain self-sufficient no matter what obstacles they encounter.

For the most part he has achieved this, although Sexton, Murray and Furlong remain well out in front in their respective positions.

I don't think an Ireland squad has ever been in better shape one year out from a World Cup.

Plenty can change in the next 12 months but seeing it all unfold will be fascinating.

Let the countdown begin.