Borussia Dortmund teenager Karetsas hospitalised after slumping to turf in Champions League

Borussia Dortmund teenage star Konstantinos Karetsas was taken to hospital for treatment after slumping to the turf 25 minutes into his Champions League debut Tuesday.

"Konstantinos Karetsas had to leave the field due to circulatory problems," Dortmund said in a statement. "Kosta is doing well under the circumstances and is on his way to the hospital for further tests."

Facing Villarreal, the 18-year-old Greece prospect passed the ball to a teammate then signaled his distress to the referee before sitting on the grass.

Karetsas was treated laying down then taken away on a stretcher. The score was 0-0 at the time.

"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 broadcaster Amazon Prime.

Karetsas and his Greece teammate Giannis Konstantelias were marquee signings for Dortmund in the summer -- former Belgium youth international Karetsas for €30 million (£25.7m/$34.9m) from Genk and Konstantelias for €26m (£22.3m/$30.2m) from PAOK.

Konstantelias' season was likely ended last month by an ACL injury on his Bundesliga debut.

Dortmund went on to win Tuesday's match 3-2 thanks to an own goal from Renato Veiga and a late brace from Serhou Guirassy on his 100th appearance for the club.

Information from the Associated Press contributed to this report.