We do have player with the profile capable of filling in the requirements for the system
"I think they have the personnel to do it. If you look at the wing-backs in Coleman and Brady, they are ideal for that. Two lads who love to get forward."
That was former Ireland major tournament hero Ray Houghton telling us why he would like to see Martin O'Neill try out a three-man back-line.
Houghton is right about Seamus Coleman and Robbie Brady being able to fill in as the two wing-backs given that both are excellent going forward and because our natural strengths tend to come from balls into the box from out wide or set pieces.
But it also takes away the defensive risk of having Brady at left-back in a back-four where he can be suspect positionally as it's not his natural role.
Switzerland certainly tried to probe that side when the Norwich winger faced them, knowing that there is a potential defensive weakness there in the back-four.
Coleman as well could be freed up to attack more regularly as a wing-back rather than a full-back.
You can listen to that full interview with Houghton the podcast player:
But elsewhere in the team, there is a nice existing balance if Ireland ever feel the need for a Plan B formation.
Ciaran Clark is a natural left-sided defender, while John O'Shea is equally adept on the right of a three given his history at full-back, and the likes of Richard Keogh or Shane Duffy are available centrally.
Further forward is the area that would also be of importance to help the formation to work, especially if opposition sides nullify the most obvious strength of a 3-5-2, 3-4-3 or 5-3-2 which is width in attack.
The formation would not require two holding midfielders which would mean only one of James McCarthy or Glenn Whelan is required with the extra defensive cover already existing behind, and it would allow Wes Hoolahan for example to take on a more deeper play-making role to shuttle forward, along with a third player option who can either be more midfield based or more forward-line suited.
Shane Long, Wes Hoolahan and James McClean ©INPHO/Donall Farmer
And if it is a more midfield based option for the third man, it is a system that allows for a front two (for example Shane Long and Jon Walters) without losing ground in midfield if one centre-back is given licence to step forward from the back when in possession.
Certainly, there is a fantasy football element to this kind of talk and the go-to formation will be - and should be - a 4-5-1, 4-4-1-1 or 4-2-3-1 because the players are more accustomed to it.
But for a Plan B, Houghton's back-three suggestion may well be worthwhile given the profile of players O'Neill has at his disposal.