WASHINGTON – U.S. men’s soccer team coach Gregg Berhalter hinted this week that he would experiment in Wednesday’s Gold Cup warm-up game against Jamaica. He did so, and the experiments ended up being duds.

With a squad of mostly reserves playing a different formation from the usual, the Americans fell to Jamaica, 1-0, before a crowd of 17,719 at D.C. United’s Audi Field.

Seven regulars who are likely to play in the Gold Cup got the night off, including centerback Aaron Long, midfielder Weston McKennie, and forward Jozy Altidore. Jackson Yueill, a 22-year-old who was invited to training camp even though he isn’t on the Gold Cup squad, started in midfield.

The backups kicked off in a 3-4-3 formation instead of Berhalter’s usual 4-2-3-1. Berhalter and general manager Earnie Stewart believe in continuity of tactics, but the coach explained after the game: “One of the objectives of this first camp was to play an alternate formation, and we achieved that. I think there’s tweaks we can make to the formation to make it function better.”

Jamaica was the better team for most of the night. At one point, left wingback Antonee Robinson played a pass on the ground across central midfield to no one. Meanwhile, Jamaica’s Keon Lambert forced Coatesville-born goalkeeper Zack Steffen to make a few saves.

Just before the hour mark, Berhalter ditched the 3-4-3 for the 4-2-3-1 by replacing centerback Tim Ream with right back Nick Lima. Winger Jonathan Amon, a promising 20-year-old who plays in Denmark’s league, also entered, replacing Yueill.

While the substitutes were settling in, Jamaica’s Shamar Nicholson scored his first international goal with a 25-yard curler. The gold-clad Jamaican fans scattered around the stands reveled in the moment.

Berhalter made more moves in the next few minutes, most notably the introduction of attacking midfielder Duane Holmes. A 24-year-old Georgia native, Holmes helped English club Derby County reach the promotion playoff final of England’s second tier, coming up just short of a berth in the Premier League.

Josh Sargent recorded the U.S.' only shot of the game in the 88th minute off a nice turn in the 18-yard box. Andre Blake dove low to his right to palm the ball away.

The second tune-up, Sunday against Venezuela in Cincinnati (2 p.m., Fox and UniMás), should look quite different. Berhalter will announce the Gold Cup squad of 23 players on Thursday morning, and will likely play his first unit Sunday. It will include star playmaker Christian Pulisic, who’ll join the squad Thursday after getting some time off following the end of the European season.

“Some guys you could tell that, I think, the moment of, ‘Okay, am I going to make the team or not?’ was wearing on them,” Berhalter said. “And that’s never nice. It’s never nice for it to come down to one game or something like that. I felt for the guys.”