Seven players are uncapped: Stefan Frei, Keegan Rosenberry, Taylor Kemp, Walker Zimmerman, Sebastian Lletget, Kekuta Manneh and Chris Pontius. Frei and Manneh will need FIFA clearance to play as they are foreign-born.
Two capped players are returning to the national team after not playing under Jurgen Klinsmann: Chad Marshall (who debuted under Arena in 2004) and Dax McCarty (captain in his last appearance in 2011).
Nine others played for the USA in 2016 but won't be in camp: Tim Howard, Kyle Beckerman, Matt Besler, Clint Dempsey, Matt Diskerud, Ethan Finlay, Lee Nguyen, Tony Tchani and Brandon Vincent. Howard and Besler are coming off surgery while Dempsey has not played since being diagnosed with a heart condition last summer.
Arena said he'd try veteran midfielder Graham Zusi out at right back, Kellyn Acosta as a defensive midfielder -- his position at FC Dallas -- and Gyasi Zardes as a winger.
The most notable absentee: young Seattle Sounders
midfielder Cristian Roldan whom Arena said he might look at later in the year.
U.S. Camp Roster:
GOALKEEPERS (5): David Bingham (San Jose Earthquakes), Stefan Frei (Seattle Sounders), Bill Hamid (D.C. United), Nick Rimando (Real Salt Lake), Luis Robles (NY Red Bulls).
DEFENDERS (10): DaMarcus Beasley (free agent), Steve Birnbaum (D.C. United), Brad Evans (Seattle Sounders), Greg Garza (Atlanta United), Matt Hedges (FC Dallas), Taylor Kemp (D.C. United), Chad Marshall (Seattle Sounders), Keegan Rosenberry (Philadelphia Union), Walker Zimmerman (FC Dallas), Graham Zusi (Sporting KC).
MIDFIELDERS (12): Kellyn Acosta (FC Dallas), Alejandro Bedoya (Philadelphia Union), Michael Bradley (Toronto FC), Benny Feilhaber (Sporting KC), Jermaine Jones (free agent), Sacha Kljestan (NY Red Bulls), Sebastian Lletget (LA Galaxy), Kekuta Manneh (Vancouver Whitecaps), Dax McCarty (NY Red Bulls), Darlington Nagbe (Portland Timbers), Chris Pontius (Philadelphia Union), Wil Trapp (Columbus Crew).
FORWARDS (5): Juan Agudelo (New England Revolution), Jozy Altidore (Toronto FC), Jordan Morris (Seattle Sounders), Chris Wondolowski (San Jose Earthquakes), Gyasi Zardes (LA Galaxy).