Borussia Dortmund said on Monday striker Sebastien Haller has left their pre-season training camp in Switzerland after a tumour was found in his testicle.
Ivory Coast’s Haller joined the German club earlier this month as a replacement for Erling Haaland, who has signed for Manchester City.
“In the course of intensive medical examinations, a tumour was finally discovered in the testicles during the course of the day,” Dortmund said.
“During the coming days, further examinations will take place in a specialised medical centre,” they added.
Dortmund paid Ajax 31 million euros ($31.5 million) for the 28-year-old after he scored 47 goals in 65 appearances for the Dutch side.