Juergen Klinsmann has often compared building a soccer team to solving a puzzle. It isn't until you start putting the pieces together that you get a true idea of what the picture will look like.
And that's what Klinsmann, who finalized his 23-man World Cup roster last week, will begin working on Tuesday when his U.S. team meets Azerbaijan at Candlestick Park in the first game in its three-game sendoff series.
"We want to see now … that they have a better understanding for each other on the field. Defensively and also offensively," the coach said of his players. "We want to just see kind of step by step things improving, which we give us more confidence.
"There's a lot of work right now going on on the training field. And it's just great to go out on a real field and measure yourself with a team."
But many of Klinsmann's players will be measuring themselves against each other as well. Three weeks before its World Cup opener, the U.S. appears undecided on three of its four starters on the back line, Matt Besler being the lone exception. There are also two positions open in the midfield flanking Jermaine Jones and Michael Bradley and perhaps another at forward, depending on how Klinsmann uses Clint Dempsey. That leaves as many as six of the team's 11 lineup spots unsettled.
"We will definitely experiment here and there because we want to give the guys as much playing time as we can," Klinsmann said. "But we also want to already see a flow in our game. There's a lineup that looks in our eyes very strong. And very close to the one maybe we see in three weeks.
"So we'll try to kind of fit both. But it's not easy."
Azerbaijan isn't likely to offer much of a test. The former Soviet republic, which didn't become an independent nation until 1991, has never qualified for a World Cup or European Championship and is ranked 85th globally, its highest ranking.
And the U.S. is the only World Cup qualifier that even bothered to schedule a tune-up with Azerbaijan, almost certainly in a nod to its coach, former German national team player and coach Berti Vogts, a longtime Klinsmann confidant who will become a special assistant to the U.S. team after Tuesday's game.
The U.S. will have stiffer tests next week when it meets Turkey and Nigeria before leaving for Brazil and its World Cup opener against Ghana on June 16.
Yet, for all the things that remain up in the air, there is one question that could be answered Tuesday: with Landon Donovan gone, who will wear No. 10, a revered jersey number that usually goes to a team's most dangerous attacker.