At last summer’s World Cup, U.S. national team coach Bob Bradley had a few dilemmas involving his lineup, most notably who to pair in central midfield and what the right combination would be at forward — without, perhaps, the right answers on the roster.

As the United States prepares for a friendly against world power Argentina on Saturday at New Meadowlands Stadium in East Rutherford, N.J. — Bradley’s first opportunity to begin shaping the roster for this summer’s CONCACAF Gold Cup — the issues he faces are centered on a different yet welcome predicament.

The American roster and talent pool now possesses greater depth, specifically in the midfield, which likely will result in a shift in tactics as Bradley searches for the best possible lineup.

A number of proven midfielders — Landon Donovan, Clint Dempsey, Maurice Edu, Michael Bradley, Jermaine Jones and the injured Stuart Holden — have left Bradley with difficult decisions to make regarding who starts, what formation to play and where those players will line up within the different formation options.

It’s the most visible sign of the advancement of the national program and the development of young players who are having an earlier impact on the international stage.

“We have certainly tried now in different ways to tweak things tactically so we could see different variations, use guys in different ways,” Bob Bradley said. “Going forward, we’re trying to fine-tune the options, get players to understand their roles on different days. I think we’ve got some good possibilities and these two games coming up, starting [Saturday], give us a chance to size up the variations there and see what it looks like in a game.”

The U.S. experimented with a 4-2-3-1 lineupin a friendly against Colombia last year, and many expected that strategy to continue into this summer’s Gold Cup. The expectations were that Holden likely would play the central role in front of two holding midfielders — Michael Bradley and either Jones or Edu — with veterans Donovan and Dempsey on the wings.

With Holden going down last weekend with a knee injury that will sideline him six months, that formation may change. Or, Edu could slide forward and play atop a triangle with Bradley and Jones.

That there is no clear-cut answer only speaks to the depth and versatility of the player pool from which Bradley is selecting.

“I think we definitely have talent regardless of what formation we play to be well-suited” for that formation, Edu said. “Whether we play 4-4-2 or 4-2-3-1 or 4-3-3 or 4-5-1. Whatever the case is, I think we definitely have the players and the ability to be flexible in the different formations we can play.”

While the United States has traditionally started with a more traditional 4-4-2 lineup, players say that identity has shifted in games to suit whatever tactical changes are necessary. Specifically, Michael Bradley said the team has moved easily to 4-2-3-1 and even 4-1-4-1 formations.

Bob Bradley said the team has played with different formations during his tenure, pointing to specific games during the second round of World Cup qualifying and to World Cup games in which they changed tactics in-game. That the Americans have experience doing it, Bob Bradley said, shows the maturity of a team that is capable of coping with whatever tactical decision is made.

Now, though, the change appears to be more intertwined with the team’s identity and philosophy. How they adjust, Bradley said, may dictate whether this team can build on its past successes.

“The fact that we’ve had experience together, know each other, had success, and now how do we build on that?” Bradley said. “All these tactical things are part of that because good teams have an understanding of how to adjust things slightly for opponents, how to adjust in a game and hopefully we can keep improving in those things.”

U.S. soccer note: The U.S. men’s national team will play World Cup champion Spain on June 4 in Foxborough, Mass., the U.S. Soccer Federation announced on Friday. The game, which will come three days before the United States starts group play against Canada in the CONCACAF Gold Cup in Detroit, will be televised by ESPN and Univision.