NOW ASSEMBLED IN DALLAS ahead of Wednesday night’s friendly against Ecuador (8pm ET, ESPN2, UniMas, UDN), the full U.S. men's national team is beginning its final preparations ahead of Copa America Centenario.

Brad Guzan was named the starting goalkeeper for the tournament despite a rough season with Aston Villa. Timothy Chandler informed U.S. Soccer staff that he was not injured in Eintracht Frankfurt’s relegation playoff victory. Geoff Cameron will miss the game against Ecuador with a sore hamstring.

Ecuador, ranked No. 12 in the world by FIFA, will open up its Copa America campaign June 4 against Brazil at the Rose Bowl in Pasadena, Calif.  Wednesday's match will be a good test for Jurgen Klinsmann and company, and here are some interesting storylines to follow in the game. 

Fabian Johnson's status?

Fabian Johnson has not played soccer since April 24 due to a groin injury. He missed the final three games of Borussia Monchengladbach’s season with this injury and was also forced out of the last two U.S. World Cup qualifiers in March.

After missing so much time, what is his fitness level? How much rust will he have to shake off before June 3? Will he have an opportunity to do so?

While Johnson is predominantly a midfielder for his club, he has featured mostly as a fullback for the United States. On the Copa America roster, only Johnson and Chandler have played left back under Klinsmann, and it's not at all clear if either will be available for duty Wednesday night. (Chandler started for Eintracht on Monday.)

FC Dallas midfielder Kellyn Acosta isn’t on the final Copa squad but is on the roster for Ecuador and could play left back. If Johnson is unable to suit up in this crucial Copa preparation match, it will be a big disappointment for Klinsmann. If Johnson is able to play, will he be anywhere near 100%? And will he be putting himself at further risk of injury? There's lots to consider with the No. 1-ranked player in the ASN 100.

Christian Pulisic and Darlngton Nagbe

The core of the U.S. men's national team has remained mostly static over the past two years. The two most prominent additions to the team, Christian Pulisic (who earned his first cap in March) and Darlington Nagbe (who earned his first cap in November), both made the Copa America Centenario team.

Nagbe, 25, is very skillful and technical but it has always been tough to find a set position for him, even among those who have known him for a long time. 

“Darlington has been an enigma, even for me, to find the right position, and I’ve known him nearly 10 years,” Caleb Porter told ASN last November. “It’s just that he doesn’t fit a position. For really special players, unfortunately, there are formations. If you adopt really rigid formations, then the player doesn’t fit.”

After instituting a formational switch last fall, the Timbers took off with Nagbe at the helm and cruised to the MLS Cup.

Nagbe likes freedom but with Michael Bradley and Jermaine Jones also roaming around the U.S. midfield as they see fit, where does that leave Nagbe? The Liberian-born midfielder can help teams win but will Klinsmann find the right fit for Nagbe the same way Porter did last year?

The game against Ecuador will offer clues, perhaps, on Nagbe’s role within this team.

The same goes for Pulisic. His position, left-sided attacking midfielder, is a bit more conventional but despite coming on strong with Borussia Dortmund in 2016, he is just 17-years-old. Will Klinsmann start the gifted teenager in crucial games? The coach just might do it if Pulisic shows well in the next two friendlies.

The Bradley-Jones pairing

The Michael Bradley and Jermaine Jones central midfield pairing predates Klinsmann on the U.S. national team but it has never really looked particularly strong. Typically, when one player is playing well, the other is not. 

Despite that, both are strong candidates to start throughout Copa America Centenario. Bradley is the captain, after all. And even at age 34, Jones is a Klinsmann favorite who is on a great run of form with the Colorado Rapids. Will new players like Perry Kitchen, Pulisic, or Nagbe perhaps change the dynamics of the Bradley-Jones partnership? Will Klinsmann better define their roles in the midfield so that they are on the same page? 

Against Ecuador, Bradley and Jones will face their toughest test together in nearly a year. It will be interesting to see if that pairing continues to be less than the sum of its parts.