Reyna's return was good news for Borussia Dortmund, which has won nine of 10 Bundesliga games in 2020 but is battling injuries.
Star Marco Reus suffered a groin injury during a DFB-Pokal match in February and has not played since then, though Dortmund coach Lucien Favre downplayed reports that Reus won't return this season.
Frenchman Dan-Axel Zagadou has been ruled out for the remainder of the season with a knee injury suffered small-sided training in April while fellow defender Mats Hummels had to leave the game against Wolfsburg with an injured Achilles tendon.
Midfielders Emre Can and Axel Witsel both missed the 4-0 win over Schalke 04 in the first game back after the two-month lockdown though Can did play the second half on Saturday at Wolfsburg.
Reyna was picked to start against Schalke 04 because English winger Jadon Sancho was still working is way back to full fitness after a calf injury. For the second game in a row, Sancho came on as a second-half substitute.
Favre says injuries are inevitable with the restart after limited group training.
"It is a danger," he said before the Wolfsburg game. "You're not training normally and suddenly, four or five days before a league match you have to train differently -- one-on-one, tackles in the air and on the ground, forward and backward and so on. It's not a big surprise to me. We'll see this happening in the future, too. Of course, it's quite normal."
Reyna has been getting playing time ahead of Mario Goetze, scorer of the overtime winner for Germany in the 2014 World Cup final. Goetze hasn't started a Bundesliga game in 2020 and will leave at the end of the season, but sporting director Michael Zorc says Dortmund needs everyone, even the out-of-favor Goetze.
"There are still many games ahead of us," he said, "and we need to count on every single player until the end of the season."