Sebastien Haller says he has completed the first step of his treatment after being diagnosed with a testicular tumour.
Borussia Dortmund's former West Ham forward complained about feeling unwell following training on Monday and immediate medical examinations detected the tumour.
Posting a picture from his hospital bed on Thursday, a smiling Haller tweeted: 'Hello everyone, I wanted to let you know that Step 1 has been completed!
'I would like to thank the @BVB (Dortmund) and the medical team who were exceptional with me.
'A big thank you also to all the nursing staff of the hospital for their support - benevolence.'
Haller added prayer and flexed biceps showing strength emojis to the tweet.
The 28-year-old Ivory Coast international joined Dortmund from Ajax earlier this month for a reported £27million.
He signed a four-year deal, after scoring 32 goals in 36 appearances in all competitions for the Dutch club last season.
Haller spent one and a half seasons at West Ham, making over 50 appearances, before the Hammers sold him to Ajax for £20.25m in January 2021.
Dortmund quote tweeted Haller's message and said: 'Always a smile on his face...get well soon Seb!'
West Ham replied to their former player's tweet: 'We're all with you, Seb!', adding a heart emoji.
