The Borussia Dortmund striker, Sébastien Haller, has said he will undergo surgery to remove a testicular tumour. The 28-year-old, who previously played for West Ham and Ajax, has been undergoing chemotherapy after being diagnosed with testicular cancer in July. Haller wrote on Twitter: “As planned from the beginning, different possibilities were considered following the chemo. I tell you that the fight is not over for me. “I will have to undergo an operation to permanently end this tumour which keeps me away from the pitch,” he added. “I want to thank you all for the messages of support and the strength you give me in this ordeal. Looking forward to seeing you all soon.” The centre-forward spent 18 months with West Ham after joining in 2019 for a then club-record £45m from Eintracht Frankfurt. He moved to Ajax in January last year before signing for Dortmund this summer. Haller, who has scored four goals in 15 appearances for the Ivory Coast national team, appeared at the 2022 Ballon d’Or ceremony in Paris last month, where he presented the Yashin Trophy award to the Real Madrid keeper, Thibaut Courtois.