Reyna, son of former U.S. World Cup captain Claudio Reyna, struck in the 35th minute on an angled shot in the season opener against visiting Mönchengladbach. The assist was credited to another 17-year-old, Jude Bellingham, an Englishman making his Bundesliga debut.
Early in the second half, Reyna drew a penalty kick, which Norwegian forward Erling Haaland converted. Later, Haaland, 20, scored again in the 3-0 victory. Reyna played 79 minutes.
Last season, Reyna appeared in 15 league matches and started twice.
Saturday’s goal was not Reyna’s first with Dortmund’s first team: He scored in German Cup matches in February and last Monday. Before the first-team call-up, he starred for the under-19 squad.
In preseason this summer, he scored four goals in three first-team matches.
Reyna rose through New York City FC’s youth academy in MLS before going abroad. He is a prominent figure in U.S. soccer’s young corps of players overseas. Others include Pulisic, who turned 22 on Friday; Juventus midfielder Weston McKennie, 22; Ajax defender Sergiño Dest, 19; Werder Bremen forward Josh Sargent, 20; and RB Leipzig midfielder Tyler Adams, 21.
Gregg Berhalter, coach of the U.S. national team, has been planning for months to reward Reyna with his first assignment. However, the novel coronavirus pandemic canceled international matches and delayed 2022 World Cup qualifying. The U.S. Soccer Federation is aiming to conduct a European-based training camp and at least one friendly in November.
Reyna has played for the U.S. under-15 and under-17 national teams. He is a prime candidate next summer for the Olympic squad, which is primarily for players 23 and under.
In England’s third flight, U.S. winger Lynden Gooch, 24, scored a terrific individual goal four minutes after entering in the second half of Sunderland’s 2-0 victory at Oxford.