Martin O'Neill has suggested that he may experiment with that set up against Mexico
Over the next two weeks, Ireland have three international fixtures to contend with.
But it's the third of those that we will really keep an eye on as a victory over Austria in Dublin on June 11th would be a big step on the way to helping us qualify for the 2018 World Cup.
Before then, a match against Mexico in New Jersey and then two-time World Champions Uruguay at the Aviva Stadium await.
Speaking on Monday, Ireland manager Martin O'Neill has suggested that he will experiment with a back three and two wing backs, which could result in a 3-4-3 shape.
That template of course has gained popularity in the Premier League due to the success Chelsea have found by using it under Antonio Conte.
The Italian switched to that formation after a 3-0 defeat to Arsenal earlier in the season and the Gunners themselves used it to perfection when they beat their London rivals in Saturday's FA Cup final.
Pep Guardiola occasionally used a back three at Manchester City last season as well, while Everton and Tottenham were among those to also make sporadic use of three-man defensive templates.
For Ireland, a back four is likely to remain the template going forward but there is no harm experimenting with a back three and wing backs because there are players available to make it work on paper. And one must underline "on paper" as other technical issues would need to be ironed out.
Wing backs are key and the versatility of Robbie Brady makes the left side work. At times, he has been a halfway house between a left back and winger (when he is not playing inside) and one could imagine him fitting in comfortably as the key outlet up and down the flank with a left sided centre back behind him to reduce some of the defensive responsibility.
On the other side, Ireland captain Seamus Coleman will be absent for months as he continues to recover from the broken leg suffered against Wales. But when he returns to fitness, he is a natural for the role of a right wing back given his attacking instincts.
Those same attacking instincts mean Cyrus Christie could also be well suited to a wing back role.
Among the three centre halves, a defender who is capable of playing out from the back is a necessity and the presence of Marc Wilson, who can play in midfield and as a left sided centre half, in future squads would provide that option.
Further forward on paper, the three forwards can play a little closer together than in a 4-2-3-1 which could see Jonathan Walters on an inside right that he has occupied before in other systems, Shane Long through the middle and another support player to the inside left as well as more dynamic central midfield behind which does not necessarily necessitate a strict holder.
Ultimately though, it will be about experimentation against Mexico and most of the aforementioned players will be absent for that first friendly. But that's what friendlies are for... a chance to try things that may come in useful some way down the line.