fifth-place finishers, currently Uruguay, go into a play-off against minnows Jordan.
It is a scenario that is far from unfamiliar to Uruguay, who have found themselves in this position in each of the previous three World Cup qualifying campaigns as well.
For the 2002 finals in Japan and South Korea, Uruguay overcame a 1-0 first leg loss to defeat Australia 3-1 on aggregate to reach the finals.
Four years later, though, and they faced the same opponents, only to lose 4-2 on penalties after both sides won their home leg 1-0.
Four years ago, they squeezed past Costa Rica 2-1 on aggregate but there can be no denying that in Jordan, they would face their least challenging opponents yet in such a play-off.
Avoiding that possibility seems highly unlikely as Uruguay trail both Ecuador and Chile, in third and fourth in the group, by three points, while those two face each other in Lima.
A draw between them would ensure both progress and while no-one is yet screaming about a stitch-up, there is the acceptance that a play-off spot, which is the least Uruguay will end qualifying with, is a near certainty.
Even Uruguay coach Oscar Tabarez has been talking up the value of qualifying through that route, dismissing the possibility that his side could lose to Jordan, ranked 73rd in the world compared to Uruguay's seventh.
"I don't share the view that the play-off is an unworthy route to reach the World Cup," he said.
"We made it to South Africa that way in 2010 and ended up finishing fourth. We're not going to the World Cup through the window or the back door."
That assertion perhaps comes from the knowledge that they could beat Argentina in Montevideo on Tuesday and see a winner in the match between Ecuador and Chile, and yet still finish fifth on goal difference.
In that respect they trail Ecuador by six and Chile by four having scored far fewer.
Knowing that a heavy defeat is the only likely way they would fail to progress automatically, neither Chile nor Ecuador can realistically be expected to take too many risks, particularly the hosts, who would have already qualified but for losing a 3-0 lead against Colombia on Friday to draw 3-3.
Had they held on, they would have joined Colombia and runaway group leaders Argentina as having already qualified.
Ecuador all but ensured their place by beating Uruguay 1-0 in Quito. They would need to lose 3-0 in Santiago and see Uruguay beat bitter rivals Argentina by the same score to drop into the play-offs.
Elsewhere, pride is all that is at stake as rock bottom Bolivia travel to Peru, as well as in Asuncion where second-bottom Paraguay host Colombia.
Paraguay v Colombia
Chile v Ecuador
Peru v Bolivia
Uruguay v Argentina