With Decision Day approaching, Argentina is on the outside looking in at the 2018 World Cup.

Yes, the 2014 runner-up and the best player in the world might not be in Russia next summer.

Lionel Messi and his bizarrely ineffective Albiceleste travel to Ecuador on Tuesday for their final World Cup qualifier as the sixth-place team in South America. They are behind fifth-place Peru on the second tiebreaker, total goals scored. The top four teams in the table qualify directly. That fifth-place side gets New Zealand in a two-leg playoff in November.

So what does Argentina need on the final day to save us all from suffering through a World Cup without Messi?

It can qualify directly with a win in Quito and at least one of the following:

• A Chile loss or draw in Brazil

• A Colombia-Peru draw

• A Peru win over Colombia with a margin of victory inferior to that of Argentina

Even if none of those occur, but an Argentina victory does, the playoff against New Zealand awaits.

The Argentinians could also stay alive with a draw. They could even finish fourth with a draw and …

• A multi-goal Chile loss to Brazil; AND

• A Paraguay loss or draw against Venezuela; AND

• A Colombia win over Peru OR a multi-goal Peru win over Columbia.

If the Argentines get the necessary help in two of those games but not all three, a point would still be enough for fifth. But if one or fewer of those wishes comes true, a point would not be enough; they’d be eliminated.

With a loss, they could guiltily sneak into fifth place with a Paraguay loss or draw and a Peru loss to Colombia by a greater margin than that of Argentina’s to Ecuador.

OK, got all that? Good. Because there’s more. A lot more. After an insane Thursday night, Tuesday is set to be just as wild. Let’s lay out the bigger picture.

First of all, the table is tight, with staccato emphasis on both Ts:

(Team — PTS | GD (GF))
2. Uruguay — 28 | +10 (28)
3. Chile — 26 | +2 (26)
4. Colombia — 26 | +2 (20)
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5. Peru — 25 | +1 (26)
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6. Argentina — 25 | +1 (16)
7. Paraguay — 24 | -5 (19)

Second of all, only two of the six contending teams play each other. The rest are spread across the other four games, meaning all five matches are, technically, meaningful (though, as we’ll see soon, one isn’t):

Brazil v Chile
Ecuador v Argentina
Peru v Colombia
Uruguay v Bolivia
Paraguay v Venezuela

To make this as simple as possible, we’ll break it down by country. But “as simple as possible” doesn’t mean simple. Just a warning. Try to follow along …

Brazil has already qualified.

Ecuador, Bolivia and Venezuela have been eliminated.

Uruguay has all but qualified. Only one set of results could send it to the intercontinental playoff: A loss at home against Bolivia, a Colombia win in Peru, a Chile win in Brazil, and an Argentina win in Ecuador that couples with Uruguay’s loss to make up a 10-goal gap. Unlikely, to say the least.

Chile can qualify with a win in Brazil, regardless of results elsewhere. With a point in Brazil, it would qualify with …

• A Colombia-Peru draw; OR

• An Argentina loss or draw in Ecuador

… assuming Paraguay doesn’t beat Venezuela by seven or more goals. And if neither of those results happen, a draw would be enough for fifth.

The other key note is that if Chile loses by only one goal, it will be leapfrogged by either Colombia or Peru, but CANNOT be leapfrogged by both. If it loses by multiple goals, it could be jumped by both.

Colombia is in a very similar spot. It can qualify with a win at Peru. It can also qualify with a draw and …

• A Chile loss in Brazil; OR

• An Argentina loss or draw in Ecuador

… again, assuming Paraguay doesn’t beat Venezuela by seven or more goals. And, like Chile, if neither of those results occur, a draw would still take Colombia to the intercontinental playoff.

With a loss, the Colombians would likely be out of the top four, and would need both Argentina and Paraguay to fail to win just to finish fifth.

Peru can qualify with a win over Colombia at home unless Chile beats Brazil and Argentina beats Ecuador by a margin greater than Peru’s over Colombia. Three points would guarantee the Peruvians at least fifth.

With a draw, Peru could finish anywhere between fourth and seventh. Its only route to direct qualification via one point against Colombia is …

• A multi-goal Chile loss OR a one-goal Chile loss in which it scores fewer goals than Peru; AND

• An Argentina loss or draw in Ecuador; AND

• A Paraguay loss or draw against Venezuela.

It would finish fifth if two of those results occur rather than three.

With a loss, Peru would be eliminated by either an Argentina win/draw or a Paraguay win.

Argentina‘s scenarios are above.

Paraguay is the one team that needs help. A win would take it to 27 points, but anything less than a seven-goal win would see it lose out in any tiebreaker scenario. So, to qualify directly, it needs a win and …

• A Chile loss to Brazil; AND

• An Argentina loss or draw in Ecuador.

It would finish fifth if one of those results occurs rather than two. It cannot realistically finish anywhere above seventh with a draw or loss.

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Henry Bushnell covers soccer – the U.S. national teams, the Premier League, and much, much more – for FC Yahoo and Yahoo Sports. Have a tip? Question? Comment? Email him at henrydbushnell@gmail.com or follow him on Twitter @HenryBushnell.