Reyna has not played in any matches since injuring his right hamstring during the opening qualifier at El Salvador on Sept. 2. He dressed for the first time since then when Borussia Dortmund played Saturday at Eintracht Frankfurt but did not get into the match.
"With Gio and Tim, it's too early to tell," coach Gregg Berhalter said Monday. "We have 14 days until they come to camp, and those 14 days will be important.''
Major League Soccer players are training at national team camp in Phoenix through Jan. 21, and several of them will travel to Columbus, where Europe-based players report Jan. 24.
Goalkeeper Zack Steffen, midfielder Tyler Adams, defenders John Brooks and DeAndre Yedlin and forward Jordan Pefok carry yellow cards from the first eight qualifiers and would face a one-match suspension with an additional yellow card.
"What we've learned is expect the unexpected," Berhalter said. "You never know who is going to be available to play in each game. You have to be willing to adapt.''
The U.S. plays at Canada on Jan. 30 and hosts Honduras on Feb. 2 at St. Paul, Minnesota. With six games per team left, Canada leads with 16 points, followed by the U.S. (15), Mexico and Panama (14 each), Costa Rica (nine), Jamaica (seven), El Salvador (six) and Honduras (three).
The top three teams from North and Central America and the Caribbean qualify, and the No. 4 nation faces the Oceania champion -- likely New Zealand -- in a playoff for another berth. A January window for qualifiers is unusual, added only because the coronavirus pandemic delayed the start of the final round by a year. MLS players and even some based in Europe are in the midst of lengthy layoffs. Midfielder Brenden Aaronson's FC Salzburg has been off since Dec. 11.
Defender Sergino Dest has been struggling for playing time at Barcelona since Xavi Hernandez was hired as coach in November, but Berhalter sounded as if Dest's national team position was secure.
"He's a competitor and he's a guy that I can see waiting for an opportunity, and when he gets his opportunity, performing well,'' Berhalter said. "He's resilient and he has the right mindset to do it. He's been working hard. He had a little injury setback at the end of the year with his back, but he's committed to making it work.''
Players at the training camp will have three closed-door scrimmages, a regimen aimed to get them close to 90 minutes by the end.
"Then we'll be able to tell,'' Berhalter said. "The most important thing is that we can put a team on the field that can compete at a high level, because we know that's what World Cup qualifying games are about.''
Defender Aaron Long, recovering from a torn right Achilles tendon on May 15, is at his third straight training camp. He might not be ready for a game until the final three qualifiers in March.
"I'm not sure he's going to get there, but hopefully he'll be close,'' Berhalter said. "Hopefully in March we're having different conversations."
Berhalter said there have been positive coronavirus tests among players arriving at camp.
"Fortunately, most are asymptomatic and now it's just about a little bit of a waiting game,'' he said. "But that's our reality, and that's what all sports teams are dealing with.''