Reyna has not played in any games since injuring his right hamstring during the Americans' opening qualifier at El Salvador on Sept. 2.
Dortmund coach Marco Rose said Monday the club was aiming for the 19-year-old midfielder to be available after the international break.
Dortmund plays St. Pauli in the German Cup on Tuesday and Hoffenheim in the Bundesliga on Saturday, then resumes against Bayer Leverkusen on Feb. 6.
"Gio Reyna is on the right track overall, but of course, he has lost something over time," Rose said. "We have to get him playable and fit to play. Without wanting to promise too much, let's aim for the break after [the Hoffenheim game] to get him fully fit again."
The U.S. plays El Salvador at Columbus, Ohio, on Jan. 27, is at Canada three days later and meets Honudras on Feb. 2 at St. Paul, Minnesota.
Asked last week about the fitness about Reyna and other USMNT players, coach Gregg Berhalter said: "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.''
Berhalter is with several Major League Soccer players at a national team training camp in Phoenix through Jan. 21 before deciding making his roster decision for the matches.
Information from The Associated Press was used in this report.