U.S. men's soccer team coach Bruce Arena made a small round of cuts on Friday from the 31 players who've been part of this month's training camp in southern California. Union defender Keegan Rosenberry was one of them. As such, he will return to the Union to join the club's preseason training.

It might seem surprising to those observers - and there are plenty of them - who viewed Rosenberry as the top young right back on the camp roster. But Arena tipped his hand on Thursday when he told reporters he had brought Rosenberry in mainly to watch him for this summer's Gold Cup, not the two coming friendlies that serve as the prelude to March's crucial World Cup qualifiers.

"We brought in some young guys that I'm more or less looking at for potentially the Gold Cup, and I'd say that would be the case for [D.C. United's Taylor] Kemp and Rosenberry for example, and even (FC Dallas' Walker) Zimmerman," Arena said. "They're all candidates for the Gold Cup. We want to have the opportunity to see them here and then we're going to follow them during their MLS seasons before we make those decisions."

Rosenberry offered this reaction on Twitter:

Arena also released Kemp, Los Angeles Galaxy goalkeeper Brian Rowe, Columbus Crew midfielder Wil Trapp and San Jose Earthquakes forward Chris Wondolowski.

Four players had left previously. Three were injured: Seattle Sounders goalkeeper Stefan Frei (ankle) and two FC Dallas players, defender Matt Hedges (ankle) and midfielder Kellyn Acosta (knee). Vancouver Whitecaps midfielder Kekuta Manneh joined his club for its preseason trip to Wales.

The other two Union players on the U.S. squad, midfielders Chris Pontius and Alejandro Bedoya, remain with the team.

Arena's team will play Serbia on Sunday in San Diego (4 p.m., ESPN, UniMás and Univision Deportes) and Jamaica next Friday in Chattanooga, Tenn. (7:30 p.m., Fox Sports 1, UniMás and Univision Deportes).

Jamaica's squad includes Union goalkeeper Andre Blake and Bethlehem Steel forward Cory Burke. Burke made his debut with the Union's minor-league USL affiliate last year, and has played three times for the Reggae Boyz. He scored in two of those games, included a game-winning goal against Suriname in November that qualified Jamaica for this summer's CONCACAF Gold Cup.

The final roster for the U.S.-Serbia friendly:

Goalkeepers (3): David Bingham (San Jose Earthquakes), Nick Rimando (Real Salt Lake), Luis Robles (New York Red Bulls)

Defenders (8): DaMarcus Beasley (Unattached), Steve Birnbaum (D.C. United), Brad Evans (Seattle Sounders FC), Greg Garza (Atlanta United), Chad Marshall (Seattle Sounders), Jorge Villafaña (Santos Laguna/Mexico), Walker Zimmerman (FC Dallas), Graham Zusi (Sporting Kansas City)

Midfielders (9): Alejandro Bedoya (Philadelphia Union), Michael Bradley (Toronto FC), Benny Feilhaber (Sporting Kansas City), Jermaine Jones (Los Angeles Galaxy), Sacha Kljestan (New York Red Bulls), Sebastian Lletget (Los Angeles Galaxy), Dax McCarty (Chicago Fire), Darlington Nagbe (Portland Timbers), Chris Pontius (Philadelphia Union)

Forwards (3): Juan Agudelo (New England Revolution), Jozy Altidore (Toronto FC), Jordan Morris (Seattle Sounders)

You might have noticed that Zusi, a midfielder for much of his pro career, is listed among the defenders. He's likely to be the starting right back against Serbia. Arena and Zusi discussed the move earlier this month. Given the other remaining defenders on the roster, Brad Evans is probably Zusi's backup.

The only player not on the Serbia roster but still with the team is Los Angeles Galaxy forward Gyasi Zardes. U.S. Soccer said he has a "minor contusion" in his right knee, and thus won't travel to San Diego.

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