Speaking to the media earlier this month, when Reyna was asked about his future, he said: "As of right now, I'm very focused here."
However, Reyna was less sure when addressing the issue in Dallas ahead of the USMNT's Copa America opener against Bolivia.
"Obviously, just looking forward to next season, I just want to go somewhere where I'm valued and get to play a lot and have an important role on the team. Whether it's at Dortmund or somewhere else, I just want to find the best solution for myself," he said.
"I haven't really looked into it and of course, my team is working slowly behind the scenes. It's still early but all my focus right now is on Sunday and obviously the tournament coming up."