I follow two national soccer teams. The U.S., of course, but also the UAE, after working six years in Abu Dhabi.

Both teams have key matches in 2018 World Cup qualifying tomorrow.

The Yanks play at Costa Rico, trying to avoid a second defeat to open Concacaf qualifying, following the 2-1 home loss to Mexico.

The UAE, however, faces a more dire prognosis if they cannot win tomorrow night.

The Emiratis are home to Iraq, and anything less than a victory probably buries their Russia 2018 dreams.

The UAE has six points from four matches, including a victory in Japan, but if they lose a second home match — to a team below them in the Group B standings — it is hard to imagine them finishing third (and contesting the Asian federation playoffs berth), let alone second place and direct qualifying to the World Cup.

What makes this scary for the UAE is the poor form of the team of late. In a 1-0 home loss to Australia, they appeared to be in something less than peak fitness, collectively; they seemed to run out of energy at about the 70-minute mark, on a hot night in Abu Dhabi, and Tim Cahill scored to win it for Oz.

Something similar happened in Saudi Arabia last month when they held the hosts at 0-0 until the 71st minute — but then allowed three goals in the final 19 minutes to lose 3-0.

Iraq may not have tons of talent, but how mentally tough do they have to be, after the 13 years of chaos in their homeland?

Iraq is coming off a 4-0 win over Thailand, and will be feeling pretty good about their chances of climbing back into the competition — if they can get three more points and join the UAE on six.

Also scary for the UAE is that their two best players, playmaker Omar Abdulrahman and forward Ahmed Khalil, have seemed a bit out of sorts over the past four or five weeks.

Just getting to the World Cup would be huge for the UAE, marking the second time it has played in world soccer’s biggest tournament.

Some suggest that the country had hardly penetrated the consciousness of the global community before the soccer team qualified for Italy 1990 — and scored two goals, one against eventual champions Germany.

A documentary is about to be released about that team (see the trailer here), which is still talked about in the UAE by everyone old enough to have seen the 1990 World Cup.

The country has not come particularly close to making it to the World Cup since then. Until this time around, when a team that is probably the best the country has fielded in a quarter century pushed its way into the final round of qualifying.

The thinking in the Emirates was that if coach Mahdi Ali’s team didn’t qualify, it at least would come close. But a losing effort tomorrow by a team that has to be nervous would leave them in a bad way, halfway through qualifying.

The U.S. would have four months — until qualifying resumes in March next year — to stew over a pointless start in Concacaf’s “Hexagonal”, if they lose in Costa Rica tomorrow.

The Yanks will be without forward Clint Dempsey, who is still sidelined by an erratic heartbeat, and goalkeeper Tim Howard, who may be out for months with a torn adductor muscle suffered in the Mexico loss, leaving coach Jurgen Klinsmann, who neglected the goalkeeper succession issue,  to lean on rusty Brad Guzan in the Costa Rica game.

Plus, the U.S. has never won in Costa Rica in Hexagonal (final six) qualifying — five defeats in five tries, by a composite score of 14-4.

The U.S. could still win a direct berth to Russia 2018, via a third-place finish, but it doesn’t speak well about your position when someone does a story about how history shows a country can finish third with as few as 14 points, and the Yanks would have eight matches left, worth 24 points, to get up there or (preferably) past it.

So, two big games tomorrow, for this international football fan.