Borussia Dortmund's midfielder Konstantinos Karetsas lays on the pitch after collapsing during his team's UEFA Champions League League match against Villarreal [Sascha Schuermann/AFP]By The Associated PressPublished On 9 Sep 20269 Sep 2026Borussia Dortmund teenage star Konstantinos Karetsas was being treated at the hospital after slumping to the turf 25 minutes into his Champions League debut, the German club said.
“Konstantinos Karetsas had to leave the field due to circulatory problems,” Dortmund said in a statement late on Tuesday. “Kosta is doing well under the circumstances and is on his way to the hospital for further tests.”
Facing Villarreal, the 18-year-old Greek prospect passed the ball to a teammate, then signalled his distress to the referee before sitting on the grass.
Karetsas was treated lying down and then taken away on a stretcher. The score was 0-0 at the time in what became a 3-2 win for Dortmund.
“I hope and I think that everything is OK, and I hope that he’s back and fit with us soon,” Dortmund goalkeeper Gregor Kobel told a broadcaster.
Karetsas and his Greek teammate Giannis Konstantelias were marquee signings for Dortmund in the off-season. Former Belgium youth international Karetsas joined for $34.9m from Genk and Konstantelias for $30.2m from PAOK.
Karetsas was reportedly a target for many clubs after impressing at Genk last season. He set up 11 goals in 28 Jupiler Pro League appearances. He signed a five-year contract through June 2031.
“With his creativity and game intelligence, Kos will enrich our team,” Dortmund sporting director Ole Book said. “He is technically very skilled and has the ability to find quick solutions in tight spaces, especially in the final third.”
Karetsas played for Belgium’s youth teams before opting to represent his parents’ country and making his debut for Greece in March 2025. He has scored three goals in 10 international appearances.
Meanwhile, 23-year-old Konstantelias’ season was likely ended last month by an ACL injury on his Bundesliga debut.
