The 2014 World Cup is 54 weeks away. The next three will tell a lot about this U.S. national team, about Juergen Klinsmann’s methods — and about the Americans’ chances of securing passage to Brazil.

But if the first leg of this defining odyssey Wednesday evening serves any indication, the U.S. team is in for a stressful summer.

The 4-2 loss to Belgium in front of 27,720 at FirstEnergy Stadium was littered with defensive deficiency, starting in the sixth minute and resurfacing repeatedly in the second half.

Only the Belgians’ multicolored uniforms were uglier than the U.S. resistance.

Klinsmann has gathered most of his primary players for the busiest stretch in years: five games in about three weeks. Each match will grow in importance, starting with two friendlies against European elite and culminating with three World Cup qualifiers that, on paper, should yield between six and nine points.

But one of the poorest performances in Klinsmann’s two-year reign undoubtedly will rekindle questions about the Americans’ future.

“It gets us right on our toes now,” Klinsmann said. “We jump-start this [three]-week period. We take [the loss] the way it is. This is why we want to play teams like Belgium, like Germany.”

They will face another stern test Sunday afternoon against Germany at RFK Stadium. Despite traveling with a second-tier roster, the Germans began their tour with four goals in the first 24 minutes en route to a 4-2 victory over Ecuador on Wednesday in Boca Raton, Fla.

Klinsmann’s selections in central defense, former University of Maryland stars Omar Gonzalez and Clarence Goodson, were no match for Belgium, which brought a power-packed roster to prepare for a June 7 home qualifier against Serbia. The visitors were swift, organized and clinical from the start.

An instant after an American threat, Kevin De Bruyne split Gonzalez and Geoff Cameron with a through ball. As Romelu Lukaku ran onto the pass, goalkeeper Tim Howard intervened. The ball spit free to oncoming Kevin Mirallas for a 16-yard shot into the vacant net in the sixth minute.

Waves of Belgian forays threatened to expand the lead, but the Americans absorbed pressure and answered in the 22nd minute. Off a short corner kick, Graham Zusi crossed to the back side of the 6-yard box. Clint Dempsey headed it back across the box to the 6-foot-3 Cameron for a simple nod at the edge of the goal line.

Defensive problems resulted in Belgium’s go-ahead goal in the 56th minute. After Brad Davis’s giveaway in midfield, Gonzalez’s poor touch while chasing a pass into the U.S. penalty area allowed De Bruyne to cross to Christian Benteke for a fundamental finish from short distance past reserve goalkeeper Brad Guzan.

The deficit deepened eight minutes later when De Bruyne swung a cross to the back post for Marouane Fellaini’s authoritative header. Fellaini is 6-4; his blooming hair makes him look 8 feet tall.

It got worse in the 71st minute as Benteke collected Steven Defour’s pass through the heart of the defense and chipped the ball over Guzan for a 4-1 lead.

Dempsey converted a penalty kick in the 80th after Costa Rican referee Jeffrey Solis called Toby Alderweireld for a handball.

The other high notes for the Americans: Left back DaMarcus Beasley became the 13th U.S. player to make 100 international appearances, and oft-injured midfielder Stuart Holden returned from a 21 / 2-year absence by entering in the 81st minute.

Otherwise, it was a fretful night for Klinsmann’s group.

Soccer notes: The U.S. and German practices Saturday at RFK are open to the public. Admission and parking is free. Germany will train at 11:30 a.m., the United States at 3 p.m.