ON WEDNESDAY NIGHT Tab Ramos named Gedion Zelalem as the 21st and final member of his United States under-20 World Cup roster. The now-complete squad features an impressive collection of professionals at multiple positions—from Zack Steffen in goal to defender Cameron Carter-Vickers to Rubio Rubin at the tip of the spear.

Until now, however, Ramos has never had his first-choice team together at the same time. Given that, here are a few questions as the team prepares for the tournament in New Zealand. 

HOW WILL ZELALEM FIT INTO THE MIDFIELD?

Zelalem, a promising prospect in Arsenal's youth program, is a central midfielder who likes to create opportunities and help in possession—which is great. The problem? Emerson Hyndman currently plays that role for the U.S. U-20s.

Hyndman, who saw quite a bit of first-team action for Fulham during the 2014-15 season, has more professional experience than Zelalem and was the best American player during World Cup qualifying earlier this year.

Can these two play together or will one be relegated to the bench? Assuming that a defensive midfielder—probably Russell Canouse, Marco Delgado, or Kellyn Acosta—will play in front of the defenders, Ramos might want to consider a 4-3-3 formation so that both Zelalem and Hyndman can play in central roles.

The problem is that the team has always looked better in a 4-4-2 and Ramos' roster doesn’t feature the sort of central forward needed to play in a 4-3-3 or 4-2-3-1.

It seems likely that Hyndman and Zelalem will feature together in a 4-4-2—Ramos has indicated he prefers that formation—although how that will work remains unclear.

“I think the important part at this point is that we have our best guys on the field,” Ramos said. “I think we have a pretty well-compensated roster with players that can make a difference from all kinds of positions, so that will be it. I think Gedion would certainly add to the group, but it won’t necessarily change the way we play. I think that he will fit right in with what we do.”

The other option would be to bench either Hyndman or Zelalem, which seems unlikely. Hyndman is the team’s established engine and removing him from the Starting XI two weeks before the World Cup in favor of a player who has never played with the United States at any level seems risky.

At the same time, Zelalem is U.S. Soccer’s shiny new toy—someone Klinsmann has been eager to get into the team for a long, long time. In March, Klinsmann said Zelalem was ready to help the full national team right now.

So Ramos has to find a way to get Hyndman and Zelalem to play together and it is not going to be easy. Finding the right formation will be tough. Even if he does, will Zelalem and Hyndman have the necessary chemistry? What happens if they don’t?

DOES THE TEAM NEED A CENTER FORWARD?

When the U.S. U-20 team struggled at the start of World Cup qualifying, the team was creating numerous scoring chances but too often failed to deliver in front of goal. After the second game, Ramos switched from a 4-3-3 to a 4-4-2 and inserted six-foot-five target forward Ben Spencer up top. It made a world of difference and the U.S. team won all of its remaining games with Spencer scoring multiple goals and proving difficult to defend.

For the final World Cup roster, however, Ramos did not include Spencer and English club Reading would not release Andrija Novakovich, another central forward, for the tournament. As a result, Ramos's roster features five forwards—Rubin, Tommy Thompson, Bradford Jamieson, Maki Tall, and Jordan Allen—who are at their best when paired up top with a partner.

Ramos said last week that we are likely to see a two-forward setup in New Zealand.

“The thought right now is to be playing in a 4-4-2," Ramos said. "So whether that becomes a 4-4-2 in a diamond or it becomes two with two more advanced or if that becomes more of a 4-4-1-1, I think we’ll see over the next week-and-a-half."

Fair enough, but Ramos has taken a bit of a gamble with this roster. The team relied on a big central forward to survive qualifying in January. It will not have that option in the World Cup.

WHO WILL START IN CENTRAL DEFENSE?

Shortly after the U.S. U-20 qualified for the World Cup, Ramos said that he believes the youth national teams are “loaded” with promising central defenders. On this roster he brought in three centerbacks—Cameron-Carter Vickers, Erik Palmer-Brown, and Matt Miazga—with right back Desevio Payne a possible backup.

In the beginning of the cycle Miazga and Palmer-Brown appeared to be the first-choice duo. But when Carter-Vickers entered into the equation in August, he replaced Palmer-Brown, who was nursing a broken foot.

Palmer-Brown and Carter-Vickers are youngsters who are both eligible for the 2017 U-20 team. Both are very promising with Carter-Vickers perhaps the highest rated player in Tottenham’s academy and Palmer-Brown is playing for Sporting Kansas City and is seeing substantial interest from Europe – including Juventus.

Will Ramos start two very young central defenders together or will he pair one with the older Matt Miazga who has been a starter with the Red Bulls this year? If that is the case, does he bench the in-form Palmer-Brown in favor of Carter-Vickers who shined in qualifying? 

WHO WILL BE THE DEFENSIVE MIDFIELDER?

In qualifying, Kellyn Acosta started the first two games but then suffered an injury. Russell Canouse came in for Acosta and did a very good job as the team won all its games with Canouse starting. In addition, the Pennsylvania native displayed a great deal of chemistry in the midfield with Hyndman. Toronto’s Markco Delgado was injured during qualifying but is finally healthy. He is also an option.

Both Canouse and Acosta are leaders and each has worn the captain’s armband throughout the cycle. Acosta is playing well right now with Dallas but the team’s record with Canouse cannot be ignored. It is a big decision and one with no obvious answers right now.

Brian Sciaretta is an American Soccer Now columnist and an ASN 100 panelist. Follow him on Twitter.