Some celebrated outside backs are likely to miss out on the Ireland 31-man squad when it is submitted to the World Cup organisers by 5pm on Monday. No matter what way one does the maths, there may only be a half-dozen outside backs accommodated in the final shake-up, and there are 10 players vying for those places.

Such has been the curiously attritional rate of injuries to wingers, especially in the last couple of seasons, that all 10 of those outside backs who have been training at the squad’s Carton House base have played for Ireland under Joe Schmidt.

Indeed, nine of them have played on the wing, and in total the 10 outside backs named in the original 45-man squad have amassed 323 caps. Of these 10, the least experienced at international level is Craig Gilroy, with six caps, and as he was back with Ulster this week, without having been given any game time in the three warm-up matches before the squad is to be finalised, he looks like missing out.

But of the other nine, all bar Rob Kearney will be feeling twitchy whenever their phone rings or there is a knock on the door come Sunday or Monday. So much is based on impressions in training behind prying eyes at the squad’s ring-fenced training pitch in the Carton House, and still more hinges on performances for their provinces last night and especially this afternoon.

Every available minute

Every utterance from the camp, up to and including Les Kiss and Joe Schmidt maintaining that the coaches remained open minded up to the conclusion of this process, confirms as much, as does going back on the expressed intention to trim the squad to 37 or 38 before now.

Even Tommy Bowe, a two-time starting wing with the Lions and with 62 caps, is under pressure after a less than compelling Six Nations and a relatively quiet outing against the Scots when not much ball came his way. It’s hard to think a player with his reputation, experience, aerial skills and proven finishing ability will be omitted, although it could happen.

Zebo was the other winger in last season’s Six Nations – until the denouement in Edinburgh anyway – but was generally deemed an outside bet at the start of this process. But a try-scoring and try-creating cameo on the wing and off the bench against Wales was augmented by a try-scoring start at fullback against Scotland. He provides versatility, a left-footed kicking option and an X-factor off the bench.

He and/or Bowe could yet miss out to Felix Jones, who was on the bench throughout the Six Nations and is highly regarded by Schmidt. He is dependable, more comfortable at fullback and would be an uber-positive squad member.

Yet Zebo may have convinced Schmidt that his positives outweigh the negatives.

Then there is the case of the two wingers in the Six Nations success from 2014. The odds looked lengthy against Dave Kearney making the World Cup after an underwhelming return from a serious knee injury last season, but word from the camp is that the Kearneys trained hard over the summer months and returned in prime nick.

This was underlined by the younger brother’s impact off the bench against Scotland. Another strong showing from the start today will make it hard for the coaches not to pick him. He can also provide cover at fullback.

Something different

Alas, he only lasted 34 minutes due to a recurrence of foot problems which equates, as Schmidt twice noted on Thursday, to 34 minutes of rugby in eight months. He needs to have convinced the coaches that he is not a risk. Trimble would be desperately unlucky to miss out but it could happen.

Earls himself has come from a longer way back but a strong end to last season was augmented by his performance at outside centre way to Wales. Akin to Dave Kearney, another strong showing on the wing today, thereby underlining his versatility, would also make him very difficult to overlook. Few Irish players have his acceleration and footwork, and he knows the location of the try line.

It could be that Earls is vying with Fitzgerald for that wing-cum-outside centre berth, given the latter is being tried there today. Then again, no less than Earls and the younger Kearney, the ball appears to be in Fitzgerald’s court today, and he too provides additional versatility as well as ability. By contrast, Fergus McFadden, seen more as a specialist winger, has not been involved since the first Wales match.

Admittedly, Declan Kidney did employ 30 players four years ago, but in all of this it’s probably fair to say that the selection of the last two or three places in the squad will not determine Ireland’s fate in the World Cup.

There were similar fun and guessing games eight years ago prior to Eddie O’Sullivan picking Brian Carney and Gavin Duffy as his last two outside backs ahead of Tommy Bowe and Luke Fitzgerald (Lions Test wingers less than two years later). Carney didn’t make one match-day squad and Duffy played the last 10 minutes of the last pool game against Argentina as a replacement for Denis Hickie in his final Test, by which point Ireland’s World Cup was already effectively over.

Ireland’s fourth prop at that World Cup, Bryan Young, along with two of the six backrowers, Alan Quinlan and Stephen Ferris (picked ahead of Jamie Heaslip), didn’t feature in one match-day squad either.

Schmidt and co will have looked at increasing their elbow room out wide, and one mooted option would be to take either two specialist scrumhalves (as Michael Cheika has done with his Wallabies squad) or two outhalves, as France have done and others might – hence, the most recent rumour emanating from the camp that the coaches are considering Ian Madigan as a third-choice scrumhalf.

As it is, Madigan is potentially back-up outhalf, back-up inside centre and third-choice fullback on match days. Maybe he’s going to be the water boy and drive the bus too.

Box-kicking drill

Kiss appeared to give the notion relatively short shrift during the week, and at face value it is quite a risk. For example, were Murray to sustain a short-term injury which ruled him out of a game or two, the management would not be of a mind to call up a replacement and therefore banish Murray from the tournament. That would thus leave them with only Reddan as a specialist scrumhalf for a game or two, and only Madigan as cover. There don’t appear to be many upsides to that.

Kieran Marmion has looked in better form off slimmer opportunities than Isaac Boss, but one suspects if there are three scrumhalves, Boss will go to his third World Cup.

In this there is a key difference from the Wallabies and Cheika’s probable thought process. Murray is one of Ireland’s key men, whereas the gap between Will Genia and Nick Phipps is marginal, and Nic White could be called up as a replacement at 48 hours’ notice.

A similar logic applies to outhalf. Were Sexton to suffer a short-term injury, the management would be of absolutely no mind to jettison him from the remainder for the tournament by calling up a permanent replacement. Therefore, they would need cover at 10 in the shape of Paddy Jackson, as well as Madigan.

Something has to give. The squad will have to travel light in one position. For example, picking six half-backs could leave Ireland a tad thin at inside centre, especially were anything to happen to Robbie Henshaw, but with Gordon D’Arcy and Noel Reid back with Leinster all week, Darren Cave could thus miss out.

Madigan could certainly start the second pool game against Romania at 12, but ideally one imagines the Irish coaches would not want Madigan to be their only starting option at inside centre against, say, France or in one of the knockout options. But there would always be the option of calling up Cave as a like-for-like replacement for Henshaw if the need arose. Indeed, the lack of cover at inside centre arguably makes Henshaw one of Ireland’s four most important players.

Whereas others, such as France and England, have picked four out-and-out centres, Ireland might risk just Henshaw and Payne, with one or two wingers also providing cover at outside centre. So it is that Earls started there against Wales in Cardiff, with Fitzgerald to do so this afternoon.

Up front, the intense competition in both the front and backrows may have been clarified, alas, by injuries. The management would understandably like to take Cian Healy, world-class on his day, and after continuing vibes of his slow recovery from the after-effects of neck surgery, the word from the camp was more encouraging this week. If truly fit enough to return to the bench against England, or even in the opening two pool matches, he is one wounded animal worth the risk. In addition to him, Jack McGrath (who can cover tighthead) and Dave Kilcoyne have proved their well-being.

Healy’s potential inclusion could work against Marty Moore, given how his protracted return from a foot injury compounded his recuperation from shoulder surgery, and although it’s unlikely he will travel I’d still have him in my squad. Two wounded animals out of five would be a risk, and this may have opened the door for Nathan White or, at a push, Tadhg Furlong, with Michael Bent offering options as cover for both sides. But Healy, McGrath, Kilcoyne, Mike Ross and Moore are Ireland’s five best props.

Donnacha Ryan appears to have edged out Dan Tuohy as the third lock, with Iain Henderson covering both secondrow and blindside. This would leave five other backrowers, and in light of Tommy O’Donnell’s and Rhys Ruddock’s misfortune, and with this tournament coming a tad too soon for Jack Conan, that would leave Jamie Heaslip, Seán O’Brien, Peter O’Mahony, Jordi Murphy and Chris Henry to complete the pack.