Overview
- The 18-year-old Dortmund midfielder suddenly sat down in the 23rd minute of the Champions League game against Villarreal on Tuesday, received on-pitch treatment, was stretchered off and taken to hospital.
- Borussia Dortmund said he left the field because of 'circulatory problems,' added that he is 'doing well under the circumstances,' and confirmed further medical examinations are under way.
- Belgian media cited early hospital tests that pointed to dehydration as a possible cause; Dortmund has not completed official diagnostics and is not offering continuous public updates.
- Karetsas was substituted in the 27th minute by loan signing Ethan Nwaneri, and Dortmund expect the player to miss the upcoming weekend league match but do not currently foresee a long-term absence.
- The incident follows midfielder Giannis Konstantelias’s late‑August ACL tear and has raised sharp attention to player health and short‑term squad management at Dortmund as the club balances care with competition.