Ireland's defence was not the only thing exposed in Geneva on Tuesday night, as the entire quick-fix, fast race, Euro 2020-or-bust nature of the Mick McCarthy era was also laid bare.
And it's strange that McCarthy, who handed a debut to a teenager and trusted a group of other players with the responsibility of leading the team to the Euro 2020 finals, could now find that he has to go back to the drawing board, call on the old guard again and see if they have the skillset needed to get this side over the line.
McCarthy has a lot to fix, a lot to get right, before Denmark come to Dublin next month. And while the stats are, on paper, impressive as the Republic of Ireland are top of their table and one win away from automatic qualification, McCarthy needs to perform surgery on his team and his squad in the next four weeks to avoid the awfulness of a playoff.
And that could see McCarthy forced to eat some humble pie and offer a recall to the players who, for now, have been surplus to requirements, mainly Robbie Brady and Shane Long.
McCarthy had his reasons for leaving both out of the squad for the last four internationals. Brady has been dogged by injury for almost two years now and has struggled to get game time with his club.
Long is fit but largely inactive with his club for tactical reasons and he too features off the bench all too rarely.
But the last three competitive games, if not the group to date, have shown that a group of Ireland players are just not ready to deliver on the big stage at this point in their careers.
Callum Robinson, Alan Browne, Conor Hourihane and James Collins have all made their competitive debuts under McCarthy but they have found that talking about the step-up and making the step-up are vastly different.
"The shirt is very heavy" was Giovanni Trapattoni's way of saying that pressure could be tough, especially on a young player. McCarthy admitted that in his first spell, a young player (Kevin Kilbane) struggled so badly on the occasion of his senior debut that he had to be replaced at half-time and he feared the same could happen to Aaron Connolly.
Hourihane admitted that he "froze" on his senior debut as the enormity of the occasion got to him and held him back.
And some players are also being held back by the demands of international football. The other problem is that other, more senior players, have also failed to deliver.
On the basis of their last two displays, it's hard to make a case for James McClean and Jeff Hendrick still being in the starting XI when Denmark visit.
If McCarthy needs to make drastic changes, does it then make sense to go back to the well and recall players who have not been fit enough, or good enough, in the manager's eyes?
Maybe not, but the decision by McCarthy to end Whelan's exile has been one of the best of his reign.
Brady and Long have suffered as much as any other Irish players in the grimness which followed the Euro 2016 finals.
But even if they're not fully match fit, they have more to offer than some incumbents in the squad.
In his first spell as Ireland manager, McCarthy asked for, and got, big displays from players who were having struggles at club level.
Jason McAteer did so against Holland in 2001 when he was an outcast at Blackburn, Ian Harte on a few occasions when he was not playing for Leeds, Alan Kelly also a player who shrugged off club woes to deliver for his country.
Presuming Whelan gets his role as the protector in front of the back four, a midfield of Robinson, Hendrick, Hourihane and McClean could start against the Danes next month with a fit-again David McGoldrick up front.
That midfield unit has been desperately ineffective time and again, the Irish inability to pass the ball all too evident in the most recent, goal-free, 180 minutes.
Throw Brady into the mix around the middle, find room for Long up front and Ireland could find that killer pass (Brady) or that nose for goal (Long) to deliver against the Danes.
If McCarthy goes for the same faces against Denmark, Ireland will be forced into a painful playoff.
Recalling the likes of Brady and Long is along the lines of 'let's get the old gang back together'. Desperate times and desperate measures, but it just could work.