Chicago White Sox closer Liam Hendriks has revealed he has non-Hodgkin lymphoma.
The Australian baseball star announced on Instagram he had been diagnosed in recent days.
The three-time All-Star, who was born in Perth, is scheduled to begin treatment on Monday (Tuesday AEDT).
"Hearing the word "Cancer" came as a shock to my wife and I, as it does to millions of families each year," he wrote.
"However, I am resolved to embrace the fight and overcome this new challenge with the same determination I have used when facing other obstacles in my life."
Hendriks said he is "confident" he will "make a full recovery and be back on the mound as soon as possible".
"I know with the support of my wife, my family, my teammates and the Chicago White Sox organization, along with the treatment and care from my doctors, I will get through this," he wrote.
The five-year survival rate for Non-Hodgkin lymphoma is 73.8 per cent, according to the US National Cancer Institute. Some forms are aggressive while others are slow growing.
General manager Rick Hahn said in a statement the White Sox do not expect to have an update on Hendriks' status prior to opening day.
"Our thoughts and reactions at this time are for Liam the person, not Liam the baseball player," he said.
"I know the entire Chicago White Sox organization, our staff, his teammates, and certainly White Sox fans, will rally in support of Liam and Kristi during the coming months.
"Knowing everyone involved, especially Liam, we are optimistic he will pitch again for the White Sox as soon as viable.
"In the meantime, we all will do everything in our power to support our teammate and his family as they face this challenge, while also respecting their privacy."
Hendriks was third in the majors with 37 saves and made his third All-Star team last season.
He led the American League with a career-high 38 saves in 2021, after leaving Oakland to sign a $US54 million ($A78m), three-year contract with the White Sox.
Hendriks has 115 saves and a 3.81 ERA over 12 seasons with Minnesota, Toronto, Kansas City, Oakland and Chicago.