Pomykal should be ready soon, as he's been a standout in MLS this season and there really isn't much in his way. Roldan sure is a solid MLS player, but the next time he turns in an impressive performance for the USMNT will be the first time.
The only thing is that Pomykal seems to be evolving into a very valuable #8, or maybe an "8-and-a-half" rather than a true attacking mid. There's enough quality to make a midfield of Adams-McKennie-Pomykal work, though. Hopefully this happens soon. It would be miserable to play against that midfield — work rate and defense for days, and quality on the ball, too, even if it lacked a true magician.
Longer-term, I'd love to see a true #10 emerge. The hope right now is Richie Ledezma, but it's early with him. There's Mendez, too, but he has a lot to overcome. That would give us a new look, a lot of options, and real depth in the midfield.