Borussia Dortmund's 18-year-old player Karesas hospitalized due to circulatory system issue

Borussia Dortmund player Konstantinos Karesas was taken to hospital during Tuesday's Champions League match against Villarreal due to a "circulatory system issue."

Collapsed without contact and signaled for help from the bench

The 18-year-old player went down shortly after making a pass without any contact from another player and immediately signaled to the Borussia Dortmund bench that he needed help. He received treatment on the pitch for several minutes before being carried off on a stretcher in the 27th minute at Signal Iduna Park.

Borussia Dortmund issued a statement in the second half saying that Karesas was on his way to hospital. The statement read: "Konstantinos Karesas had to leave the pitch due to a circulatory system issue. Costa is currently doing okay and is on his way to hospital for further examinations."

Joined this summer and has started every match at the beginning of the season

Karesas joined Borussia Dortmund this summer from Belgian club Genk. At the start of this season, he started all three matches in the Bundesliga and Champions League, and also made substitute appearances in the German Cup and German Super Cup.

Borussia Dortmund have already suffered injury setbacks early this season. Fellow Greece international Giannis Konstantelias, who joined from PAOK in August, suffered a torn anterior cruciate ligament in his left knee on his Bundesliga debut. The injury prompted Dortmund to loan Arsenal midfielder Ethan Nwaneri.

Borussia Dortmund have won both of their opening Bundesliga matches this season. Niko Kovac's team will host Paderborn on Saturday.