Ireland need to mix and match their team for Tonga test while keeping their big guns fresh to face South Africa… but axis of Bundee Aki, Garry Ringrose and Tadhg Beirne will be crucial

As Bundee Aki sprinted to win the race for Jack Crowley’s chip ahead, the clock read 82 minutes and 17 seconds.

Aki rallied miraculously and was then expertly offloaded to the supporting Garry Ringrose.

The outside center drew the lone defender and threw a simple pass to Tadhg Beirne to slot over and score Ireland’s twelfth try.

That willingness to keep the ball alive and try to chase down one more goal left Andy Farrell looking very pleased after the game, but the identity of the trio involved was also crucial.

Aki, Ringrose and Beirne all played the full match in extremely difficult conditions and if this is an accurate reflection of Ireland’s physical preparation – such as the excellent performance of 38-year-old Johnny Sexton after a six-month absence – it also reflects strong indication of the coach’s plans for the next two weeks.

Ireland’s World Cup fortunes will be determined by what happens between now and the night of September 23. The team Farrell chooses to play against Tonga next week will be heavily influenced by the match against South Africa.

The Irish camp is already stressing that they expect a formidable challenge against the Tongans in Nantes, but anything short of the Irish victory against a team whose only recent victories have come against Canada would be a sensational result.

The physical challenge they pose has been much advertised, but the impact of the limited but ungainly Romanian tacklers is still being attended to at the Irish base in Tours on Monday morning.

Expecting Farrell to rotate significantly, and that a key trio like Ringrose, Aki and Beirne should play the full 80 minutes suggests they will all start on the bench, at best in five days’ time.

Hugo Keenan, James Lowe, Peter O’Mahony and Joe McCarthy were the other four starters who played the full match. Two of them, Keenan and Lowe, will certainly start against South Africa at the Stade de France; Keenan is so indispensable that he could start every game Ireland plays here, regardless of whether he finishes them all.

McCarthy made his case for being picked with his performance in Bordeaux, which Farrell and Paul O’Connell may find irresistible, while O’Mahony’s excellent performance means he should also be in the 23rd spot for the South African showdown.

Seeing as how he can keep Josh van der Flier out of the starting 15 for a match of that importance seems like a tall order, but if he doesn’t start he will be among the replacements.

McCarthy is not a name many would associate with starting against the Springboks a month ago, but the job Aki did against Romania also provided an audition that Farrell simply cannot ignore.

That decision could be made easier if Robbie Henshaw’s grumbling continues. It is expected that this will not be the case; Farrell stressed that withdrawing him from the bench was a precautionary measure after experiencing tightness in his muscles on Friday.

But even if he is fit, Henshaw will not break the partnership between Ringrose and Aki. It’s one this coaching team has used before, and Aki offers two compelling strengths.

The first is its shape; he was the outstanding Irish player on Saturday, even though O’Mahony got the man of the match award. He has long been associated with power, but the subtleties he has introduced into his game under the guidance of Farrell and Mike Catt make him an even greater threat.

The second point in Aki’s favor is his long-standing power. Against South Africa, any ambition depends on withstanding a physical attack that could be devastating.

His durability and sheer strength are important assets in such a game.

No player responded better to Farrell’s call for Ireland to get things serious on his arrival in Bordeaux.

It marked a change of pace after a pleasant warm-up week in Tours where they were adored by the locals.

They are now back at that base, where the focus of everyone involved will only become sharper.

Beirne was also a player who performed well against the Romanians, and that only reminded everyone that he is most effective in the back row.

This again appears to be a move with South Africa in mind: playing Beirne as a blindside flanker frees up space for McCarthy in the second row, provides a new lineout option and also widens the Irish pack even further.

Farrell then joked with Sexton about playing him against Tonga so he can break Ronan O’Gara’s Irish scoring record. He is nine points behind O’Gara, but there will be no rush to overtake him on Saturday night in Nantes.

However, Sexton will certainly come off the bench, not for statistics, but because another half hour or so to fine-tune his return after six months could be important.

Who starts in his place is one of the interesting calls. Jack Crowley has a good case for undermining Sexton in the big matches given his ambitious playing style, confidence and excellent results at Test level since his debut.

The control that Ross Byrne provides is much appreciated, as Mike Catt mentioned again recently, and in a match that will be more challenging than many suspect, Byrne’s willingness to be pragmatic could be relied upon.

There is also a factor that Farrell would deny, but trying to get as many members of the 33-man squad as possible into a game is an ambition that, all else being equal, a coach would try to achieve.

It keeps everyone involved and makes them feel part of a building adventure.

The feeling that this odyssey will arrive in Paris at a crucial moment has only become stronger after the opening weekend.

Winning Pool B and avoiding the French in the quarter-finals is now the prize, but that will require a huge effort against the defending champions.

The team chosen for Romania showed that Ireland will aim to field as big and physical a team as possible for that match.

Fortunately for Farrell, his choices in that regard all worked on Saturday, with Beirne and Aki in particular.

Avoiding a chaotic misstep in Nantes is now the requirement, but there seems no chance this group will succumb to complacency.

The business has started and they look sharp.

The climb quickly becomes steeper and they seem ready for it.

Nantes is next, but the challenge of Paris is already waiting, catching our attention and making hearts beat just a little faster.