Borussia Dortmund’s Champions League meeting with Villarreal was overshadowed by alarming scenes after teenage talent Konstantinos Karetsas collapsed on the pitch. The 18-year-old forward was making his much-awaited debut in Europe’s premier club competition before the medical emergency forced him to leave the field.

Medical emergency unfolds in Spain

The football world was left stunned on Tuesday night as Dortmund’s emerging star Karetsas was taken to hospital after collapsing during his Champions League debut against Villarreal.

In an incident that immediately caused concern among players and supporters, the 18-year-old midfielder played a simple pass to a team-mate before appearing to struggle and signalling that something was wrong to the referee. He then sat down on the turf as the seriousness of the situation became clear.

Dortmund issue official update

Soon after the incident, the Bundesliga club released an official statement to clarify the player’s condition, confirming that the problem was linked to his circulatory system. “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.”

Speaking to the media after the final whistle, Dortmund goalkeeper Gregor Kobel shared the squad’s concern while also expressing hope over his team-mate’s recovery. “I hope and I think that everything is OK and I hope that he’s back and fit with us soon,” Kobel told broadcaster Amazon Prime.

A summer of spending and injury setbacks

Karetsas arrived at Signal Iduna Park during the summer transfer window, joining along with fellow Greece international Giannis Konstantelias as part of a major recruitment push centred on elite young talent. The former Belgium youth international cost Dortmund a sizeable €30 million (£25.7m/$34.9m) to sign from Genk, while Konstantelias joined from PAOK for €26m (£22.3m/$30.2m). Both were expected to play key roles in the club’s European campaign this season.

However, the German side has suffered a dreadful run of misfortune with their costly new signings. This latest scare involving Karetsas follows the damaging news concerning Konstantelias, whose season was likely ended last month by a serious ACL injury suffered on his Bundesliga debut. The setbacks surrounding their headline summer arrivals have left manager Niko Kovac facing major tactical problems as fixtures pile up in domestic and continental competitions.

Guirassy seals late win

Despite the shadow cast over the game by the medical emergency, Dortmund still managed to respond on the pitch and claim a hard-fought 3-2 win in Spain. The score was 0-0 when Karetsas went off, but the match later burst into life.

Guirassy, playing his 100th match for the club, made the difference with a late brace to make sure all three points went back to Germany, while also overtaking Robert Lewandowski’s tally in the process. Although the result keeps Dortmund’s Champions League hopes firmly on course, the club’s main concern remains the health and well-being of Karetsas.