George Hook: Joe Schmidt already knows his 31 and I think it's bad for Cian Healy

If all eventualities are catered for, the chances of falling flat on any given outing are greatly diminished. Nothing is ever fool-proof, of course, but wisdom and preparation are mortal enemies of bad luck.

Despite his insistence that there are still plenty of positions up for grabs this weekend, it is difficult to argue that Joe Schmidt hasn't already decided on his 31-man World Cup panel. The Ireland coach has had close to eight weeks of intensive training in which to survey his options and test out potential combinations.

And, with just two Tests remaining until the pool stage begins next month, I think it's safe to assume, barring disaster, that those involved in the Aviva match-day squad tomorrow are already assured of their World Cup places.

This spells trouble for Cian Healy. If rumours about the Leinster prop are to be believed, his recovery from surgery is still some way down on where it should be.

With Jack McGrath a certainty to start in the opening pool game against Canada next month and Healy still struggling to prove his fitness, it is reasonable and proper that Schmidt makes alternative plans at this late stage.

Dave Kilcoyne will be the main beneficiary if, as suspected, Healy is deemed too much of a risk to include in Monday's final squad. All things being equal, the Munster loosehead would probably have lost out to the perceived wisdom that Michael Bent, as a fifth prop, can cover both sides of the scrum.

But with Healy struggling and McGrath deemed automatic first choice in his absence, Kilcoyne will more than likely take a place on the plane as a second loose-head option.

Tadhg Furlong's inclusion on the bench tomorrow also puts him ahead of Martin Moore in the pecking order. Moore's own struggles with injury appear to have cost him dearly and though Furlong hasn't had much game time himself in recent months, it would appear that Schmidt favours taking the Wexford man ahead of his Leinster colleague.

The 23-man squad to play Wales tomorrow also dispels the ridiculous rumour that Ian Madigan is seriously being considered as scrum-half cover. It is one thing to be a talented and versatile footballer; but to expect a player to cover such a specialised position with no experience whatsoever would be a monumental gamble and not in keeping with the coach's form.

As I discovered to my cost on live television some years back, when Mauro Bergamasco was parachuted into the Italy team during the Six Nations, scrum-half is not for everyone.

Isaac Boss ain't the player he was five years ago, but he is certainly preferable to a guy with zero game time behind the scrum. If Madigan goes to the World Cup, it will not be as a back-up scum-half.

Donnacha Ryan appears to have beaten Dan Tuohy to the punch for the last remaining second-row slot. With Iain Henderson assured of his place as a lock and back-row option, Ryan seems the natural choice to travel following his recent return to fitness.

Tomorrow, Wales will provide Ireland with their biggest test of the warm-up series thus far. Warren Gatland has selected his strongest available starting 15 and with time running out to get his players battle-hardened for the forthcoming Pool of Death, Wales will be looking to perform at full throttle.

Luke Fitzgerald has played very little rugby at centre in recent years, but his ability to attack and defend in the 13 channel will be tested to the limit against Jamie Roberts and Scott Williams.

Williams is not as poor as his last performance in Cardiff suggested and with ground to make up in the eyes of his head coach, the Scarlets player is bound make life difficult for the inexperienced Leinster man in front of him. Either way, Keith Earls will be an interested spectator on the sideline.

Jonathan Sexton's return is a massive boost for his outside backs. The St Mary's playmaker consistently gets the most out of those around him, so the three-quarter line will never have a better opportunity to showcase their talents.

For Ireland fans, this is also the final chance to observe one of the game's great leaders in action on home soil.

Paul O'Connell's loss to his country will only be truly appreciated when he is gone, but to witness the Limerick lock in full flight is to appreciate a supreme athlete at the height of his powers.

One thing is certain: Munster and Ireland will not be the same without him.