Borussia Dortmund striker Sebastian Haller has had to leave the BVB training camp in Bad Ragaz, Switzerland prematurely due to illness and is already back in Dortmund.
The 28-year-old Ivory Coast international complained that he felt unwell after training on Monday morning.
Following a series of thorough medical examinations conducted during the course of the day, a testicular tumour was ultimately discovered. Further examinations will take place in a specialist medical facility over the coming days.
"This news today came as a shock to Sebastien Haller and everyone else. The entire BVB family hopes that Sebastien makes a full recovery as soon as possible and that we can give him a hug again soon. We'll do everything in our power to ensure that he receives the best-possible treatment," BVB sporting director Sebastian Kehl said.
Borussia Dortmund request that the privacy of the player and his family is respected and that no inquiries are made. As soon as we have further information, we will consult with the player and inform you.