The United States begins workouts Thursday at Orlando City Stadium. (Ron Blum/Associated Press)

ORLANDO — There are almost endless permutations, enough to make a mathematician’s head spin, of how the U.S. men’s national soccer team could qualify for the World Cup by late Tuesday night.

Input the possible results in these last two U.S. matches, then forecast the scores of the other group games. Don’t forget to factor in goal differential and total scoring over the 11-month competition involving six nations.

Check the data. Check it again.

Or the Americans could avoid the maddening numbers and use the simplest math equation available to them: 3 + 3 = 2018.

With three points against Panama on Friday at Orlando City Stadium and another three in Trinidad and Tobago on Tuesday, the Americans wouldn’t have to sweat out the other statistical mutations.

No supercomputer necessary, for they will have secured passage to the 2018 tournament in Russia.

“Win the game,” Coach Bruce Arena said. “That’s the message to them. Win the game. We have no excuses. We’re not depending on other teams to help us. We’re depending on ourselves.”

The United States has been living dangerously since last fall, when it lost the first two matches in CONCACAF’s final qualifying round. In replacing Jurgen Klinsmann, Arena restored stability through the spring and summer. But with an opportunity to create distance in the race for the region’s three automatic berths, the Americans stumbled last month.

So now they find themselves with almost no room for error. Mexico (5-0-3) has clinched. Costa Rica (4-1-3) is on the verge. The United States (2-3-3) sits one point behind third-place Panama (2-2-4), which, with a victory Friday, could advance to the World Cup for the first time.

Honduras (2-2-3) also remains in the running despite a terrible goal differential, the first tiebreaker.

With a draw Friday, the United States would have to beat Trinidad and Tobago (1-7-0) and pray for help in perhaps both other matches Tuesday.

The fourth-place finisher will enter a travel-heavy, two-leg playoff next month against Australia or Syria. Four years ago, Mexico needed to take that stressful route to get to Brazil.

The United States is among seven countries — and the only one from CONCACAF — to participate in every World Cup since 1990.

“It’s a big occasion,” Arena said before Thursday’s training session. “I don’t think I need to lecture our players on the significance of the game; I think they understand that.

“We have a group of players that have been in these games since March — every game has been do-or-die for us. This is no different, but obviously as you get to the end, there’s more significance in it.”

The weight of the Panama match has not been lost on the players.

“We need three points bad,” said Christian Pulisic, the 19-year-old attacker who has become critical to the U.S. attack.

“We can’t leave this field without three points,” D.C. United winger Paul Arriola said.

“Games don’t get much bigger,” captain Michael Bradley said. “We’ve played in games where we need points and there’s been a real sense of urgency. You get to the end and our margin for error is virtually gone.”

It’s gone, in large part, because of a 2-0 defeat to Costa Rica on Sept. 1, the second defeat in four home matches. If not for Bobby Wood’s 85th-minute equalizer at Honduras four days later, the Americans would’ve arrived in Orlando in critical condition.

Emphasizing camaraderie and experience, Arena made few changes to the 25-man roster. He’ll continuing leaning on Bradley for leadership and organization in the middle of the formation and on the usual collection of defenders to protect Tim Howard or Brad Guzan in goal.

He’ll need Pulisic and Darlington Nagbe to provide sparks in the open field and the attack in general to find its way after scoring once in two outings last month.

The scoring problems have coincided with opponents focusing heavily on Pulisic and taking him out of his rhythm with bruising fouls. After recording three goals and three assists in three consecutive qualifiers, he has labored in the past three matches.

Asked if expectations on Pulisic are fair — he is already the team’s most popular player and was featured on “60 Minutes” on Sunday — Arena said: “It’s fair. It’s fair that every player needs to have a big performance in this game.”

The Americans will also need to avoid falling behind in the first half and, consequently, chasing the game, as they had to do in both matches last month.

“We want to come out flying at the beginning,” Pulisic said. “If we can get an early goal, it would be perfect.”

U.S. notes: The Americans have an 11-1-6 all-time record against Panama, including 5-0-2 in World Cup qualifiers, but the past four meetings have ended in 1-1 draws. They clashed in Panama City in March, with Pulisic setting up Clint Dempsey for a first-half goal. …

Bob Bradley, the 2010 U.S. World Cup coach who will guide MLS expansion team Los Angeles FC next season, has joined Arena’s staff for the Panama match.

“I can’t think of a greater resource to have available,” Arena said of his former assistant at the University of Virginia and D.C. United. Besides, “He’s also the father of one of our players” (Michael Bradley).

United States vs. Panama

Where: Orlando City Stadium.

When: Friday at 7:35 p.m.

TV: ESPN2, Univision, Univision Deportes.

Live streams: ESPN3, WatchESPN, univisiondeportes.com

CONCACAF standings

  1. Mexico, 5-0-3, 18 points
  2. Costa Rica, 4-1-3, 15 points
  3. Panama, 2-2-4, 10 points
  4. United States, 2-3-3, 9 points
  5. Honduras, 2-3-3, 9 points
  6. Trinidad and Tobago, 1-7-0, 3 points

Other matches

Friday: Trinidad and Tobago at Mexico, 9:30 p.m. (FS1, Univision)

Saturday: Honduras at Costa Rica, 6 p.m. (beIN Sports, Universo)

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