Here are five players from the all-MLS group that have room to gain this month:
The internet doesn't agree on much, but one issue almost universally drew the ire of the World Wide Web was Russell Canouse being left out of the USMNT's roster for November friendlies.
Nearly as integral to D.C. United's second-half surge to Wayne Rooney, Lucho Acosta and Audi Field, Canouse forced his way onto the national team landscape one interception and successful tackle at a time. Questions have been raised about whether or not Wil Trapp has the athleticism to succeed against the top opposition; there are no such queries about Canouse. If he can prove to Berhalter that he can do all the good work Trapp does in possession, and excel in the system that Trapp did for so many years under Berhalter in Columbus, he may well force his way into the discussion for the Gold Cup.
Does Michael Bradley count? For a player that has made 142 caps who has been in the team essentially since after the 2006 World Cup, it'd be more conventional to say he has something to lose.
Except he doesn't, because he's already been generally taken out of the national rotation as the program fought to get younger in 2018 without any competitive games to prepare for. Now, with the Gold Cup on the horizon, Bradley has to prove he still has the legs for the international game.
The last time Greg Garza made an appearance for the US national team, it was January 2017. He started and went 69 minutes in a goalless draw against Serbia. It was Bruce Arena's first game (back) in charge of the national team and the possibility of the USMNT missing out on the World Cup was still as farfetched the idea of hovering cars.
Oh, how naive.
Garza is back for the 2019 January camp. Looking around, left back could be his with a strong month in front of new boss Berhalter. His competition is Portland's Jorge Villafana, 29, who featured during much of 2018 but wasn't called in by Berhalter, Antonee Robinson, 21-year-old Wigan loanee, George Bello, 16-year-old Atlanta United starlet, Ben Sweat, NYCFC's 27-year-old stalwart who wasn't called in for the camp, and others. The position is wide open.
On the same thread of Garza, Djordje Mihailovic features at a position in flux for the national pool. The organization is short on No. 10s, with Christian Pulisic regular filtering through the middle to try and find the answer. A natural winger, Pulisic may be best used through the middle while on international duty. But, an emergence from Mihailovic could ease that headache.
The Chicago Fire Homegrown was a surprise inclusion to the roster, if only because he returned from a torn ACL in August. While looking fully up to speed to the untrained eye, he told MLSsoccer.com that he was still shaking the rust off.
A highly-regarded prospect that played every single minute for the Philadelphia Union in 2018, Auston Trusty has earned his shot with the senior national team. The only issue is how deep the squad is at the position. So deep, in fact, Tim Parker didn't get added to the January camp while the likes of Jonathan Brooks, Matt Miazga and Cameron Carter-Vickers are unavailable for selection while continuing their seasons in Europe.
Regardless of what happens in January, Trusty will have more opportunities. But he has the chance to keep himself in the team when healthy for the next decade with a strong performance.