Mancini, 28, said he will be undergoing chemotherapy for the next six months and is unlikely to play in 2020.
Originally from Winter Haven, Florida, Mancini underwent a procedure in March to remove a malignant tumor from his colon.
“When I went for an endoscopy and a colonoscopy, the doctors told me that they really expected to confirm that I had celiac disease, which is in your small intestine,” said Mancini. “When the anesthesia put me underwater, I thought everything was going to be fine.”
Mancini, whose father was diagnosed in 2011 with stage 2 colon cancer, wrote that he had started to wonder about a diagnosis of cancer before his doctor revealed one.
“He started by eliminating all possible things,” said Mancini. “I was still stunned by the anesthesia, but before he even said the word cancer, I said to myself, There is no way he’s about to say what I think he is about to say. And then he said it: They found a malignant tumor “tumor in my colon. “
Pro for four years at Notre Dame, Mancini appeared in 154 games last season, hitting .291 with 35 homers, 97 RBI and .899 OPS.
Mancini started her current treatment on April 13.