DaMarcus Beasley is set to train with the United States in their January camp. Kevin C. Cox/Getty Images

Juan Agudelo, DaMarcus Beasley, Matt Hedges, Kekuta Manneh and Dax McCarty weren't involved with the U.S. national team in 2016, but new coach Bruce Arena said those players and others who weren't in the mix under former manager Jurgen Klinsmann will receive invites when his first U.S. camp kicks off next month.

"Players who haven't been around in a bit will be back in camp," Arena said Friday during a live Facebook Q&A. "We're excited about looking at some of these MLS players and see if they're going to be in position to help us in 2017."

Other MLS players Arena said would be called in include Philadelphia Union pair Chris Pontius and Keegan Rosenberry; Walker Zimmerman, who plays alongside Hedges with FC Dallas; and Gambian-born Manneh of the Vancouver Whitecaps. All are uncapped. Benny Feilhaber and Darlington Nagbe will also be there. Columbus Crew winger Ethan Finlay won't be, Arena said, adding that Perry Kitchen would also miss out because of a conflict with his Scottish club Hearts.

The mostly domestic-based squad will take on Serbia in a Jan. 29 friendly in San Diego. Another exhibition is planned for the following week. The tune-ups will help prepare for a March 24 World Cup qualifier against Honduras, a match Arena called a "must win" after the Americans lost against Mexico and Costa Rica last month.

"Probably two-thirds of the pool is comprised of players from Major League Soccer, so this camp is going to be very important," Arena said. "We are going to depend on a lot of players from MLS. The January camp is going to help answer some questions we have."

The U.S. has questions particularly on the back line, the flanks and in central midfield. The U.S. back four struggled mightily against Mexico and Costa Rica. Three of the four starters from those games -- German-based John Brooks, Timmy Chandler and Omar Gonzalez, who plays in Mexico -- won't participate next month because of club commitments. Neither will regular defenders Geoff Cameron and DeAndre Yedlin -- all of whom won't be available to Arena until days before qualifying resumes.

"That's certainly an area of uncertainty," Arena said of the defense. "We're going to have to communicate with our players abroad and make sure we have a clear understanding of how we want to play and who we want to play."

One open question involves versatile Borussia Monchengladbach man Fabian Johnson, who Arena visited with during a recent trip to Germany.

"We're going to evaluate him over the next couple of months and take into account where he's playing," Arena said of Johnson. "He's either going to play on the left side of midfield or at left back."

There's also uncertainty in goal. Tim Howard is out for the foreseeable future after suffering a groin injury last month. Fellow veteran Brad Guzan has been rooted to the bench with Premier League side Middlesbrough, but is reportedly close to transferring back to MLS.

"At the moment, Tim's status for March is uncertain," Arena said. "We're not sure if he's going to recover in time from his surgery, so Brad Guzan is obviously the likely candidate to be the starting goalkeeper."