With Germany's top division becoming Europe's first major football league to return amid the coronavirus pandemic, midfielder Reyna was set to play for Dortmund against bitter rivals Schalke after he was announced in Lucien Favre's starting lineup.
However, minutes before the match, Dortmund said Reyna was injured and he was replaced in the starting XI by Thorgan Hazard, with Favre having to cope with a growing injury list which includes Axel Witsel and Emre Can. Jadon Sancho, the England winger, was also a notable absentee as he continues his recovery from a calf strain.
"There have been some difficult times, and I knew it wasn't going to be easy. But all I need to do is keep my head looking forward, eyes on the future and hopefully I can do some more pretty cool stuff," he told ESPN.
"I look up to him [Haaland] because he's done so many things in a young career, and he's a great guy.
"He's encouraged me, as he sees something in me."
Reyna has made 11 appearances since his debut on Jan. 18, most recently in the Champions League loss at Paris Saint-Germain on March 11. His replacement in Saturday's match, Hazard, set up Haaland for the opening goal as Dortmund won 4-0.
The Bundesliga's return from the shutdown forced by the coronavirus pandemic has been anticipated by sports fans around the world. However, some influential voices have questioned the comeback of football in the country.
"If health experts have made those suggestions, if the league with great expense and smart ideas has worked on concepts, you have to stick those rules," Bavarian minister president Markus Soder told Bild on Friday.