Former West Ham striker Sebastien Haller is to undergo surgery to remove a testicular tumour.
The 28-year-old, who now plays for Borussia Dortmund, has been undergoing chemotherapy after being diagnosed with testicular cancer in July.
He 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.’
Haller spent 18 months with West Ham after joining in 2019 for a then club-record £45million from Eintracht Frankfurt.
He moved to Ajax in January last year and signed for Dortmund this summer.
Haller has scored four goals in 15 appearances for Ivory Coast.
Haller had been training with former club Ajax as part of his recovery as he was rehabilitating in Holland.
After feeling unwell during Dortmund’s pre-season tour of Switzerland, he underwent tests which revealed a malignant tumour.
Haller is yet to make his debut for the Bundesliga giants and has previously opened up about the treatment he has undergone.
Speaking to UEFA last month, he revealed he has spent ‘five days at a time at the hospital, where I am hooked up 24/7’ and cannot get out of bed while the treatment is injected. He then has a two-week rest period.
‘That’s one phase, and I have to do that four times. Four phases of chemotherapy lasting roughly three weeks each,’ he added.
‘After that, depending on how my cancer is progressing and how it is spreading, I may be forced to undergo surgery.
‘A lot of people are asking me when I will be back, but there’s a lot to take into account so it’s hard to give them a straight answer.
Haller had previously spoken in August about how his family reacted to the news, with the former West Ham striker admitting his mother had struggled to come to terms with his diagnosis.
‘My wife was in shock, but she could deal with it. But.. my mum.. it wasn’t the same, because mothers are mothers,’ Haller said in an interview with ESPN.
‘I called my brothers and sisters to make sure they will be there for her, so that she wouldn’t feel alone. This is what I have done.’