If the USMNT lose, they won't definitely miss the World Cup. Just probably.

The United States will take on Guatemala on Tuesday night in a World Cup qualifier that they don't absolutely have to win. At least not mathematically. But they almost definitely have to, or they'll likely miss out on the 2018 World Cup.

After the Americans' loss in Guatemala last Friday, they sit in third place in Group C of the semifinal round of CONCACAF World Cup qualifying. They are three points back of first-place Trinidad and Tobago, and they trail Guatemala by two points for the second spot. Seeing as only the top two teams in the group advance to the final round of qualifying - the Hexagonal - the Americans are in a bad spot and need to make up ground.

Beating Guatemala on Tuesday will put them back in second place. And they should beat Guatemala, the 95th ranked team in the world that they hadn't lost to since 1988 until last week. This time they get Los Chapines at home, too, in Columbus, where the U.S. has never lost a World Cup qualifier. From there, Jurgen Klinsmann's men would need to win their final two matches of the qualifying round - at St. Vincent and the Grenadines and against Trinidad and Tobago at home - but even a win and draw would probably get them through.

What if they don't beat Guatemala on Tuesday night, though?

Anything other than a win would leave them in third place and without control of their own World Cup destiny. The Americans would then need results in other matches to go their way, even if the Americans win out. That includes potentially being dependent on St. Vincent and the Grenadines to take points off of either Trinidad and Tobago or Guatemala. That's not a joke. Their World Cup lives may hinge on the 141st ranked team in the world who play their home matches in a mostly empty cricket stadium.

Simply put: if the U.S. fail to beat Guatemala on Tuesday night, they will have a less than 10 percent chance of advancing to the final round of World Cup qualifying.

That's not making the World Cup. That's just getting to the final round, where a team that has struggled in the semifinal round would have to perform against even better teams to punch their ticket to Russia.

So is Tuesday night's contest a World Cup eliminator? Not quite. They don't have to win. But even manager Jurgen Klinsmann knows what's on the line.

"We need to win this game," Klinsmann said.

Yes, they do.