Baltimore Orioles outfielder Trey Mancini is set to make his return to Major League Baseball on Friday. The 29-year-old revealed he was diagnosed with stage 3 colon cancer last April, a month after he underwent surgery to remove a tumor.

In a personal essay for the Players' Tribune, Mancini said doctors discovered he had a tumor after some of his blood test results came back low during a physical for the Orioles. He had been experiencing fatigue for weeks. His doctors originally suspected a potential gluten intolerance. When testing ruled that out, Mancini underwent a colonoscopy which revealed a malignant tumor.

“Up until that point, most of my biggest problems or worries were all baseball related,” Mancini told MLB.com. “Going through a slump was maybe the worst thing I had gone through, personally, and I’m very lucky to have said that at that point. I’d never been through anything like this with me or a family member. So it definitely put a lot in perspective.”

I couldn’t have gotten through the past few months without Sara and the rest of my family. They give me the fight I need each day to face my challenges and push through. Thanks @PlayersTribune @ModeloUSA for allowing me to share my journey. #ModeloPartner pic.twitter.com/H76dmHu5y2

— Trey Mancini (@TreyMancini) October 19, 2020

According to Dr. Jason Klapman, a gastroenterologist at Moffitt Cancer Center, fatigue is just one of many symptoms to be on the lookout for when it comes to colon cancer. Rectal bleeding, change in caliber of stool and unexplained weight loss should also be a cause for concern.

Mancini was just 28 when he was diagnosed. Patients under 50 represent 12% of all cases diagnosed. Klapman said it’s very rare to see someone under age 30 with colon cancer. The incidence of colorectal cancer is three cases per 100,000 for people ages 25-29. 

Hereditary cancer syndromes are responsible for 10% of all colon cancers. Mancini’s father, Tony, is a colon cancer survivor, having previously been diagnosed when he was 58.

“Having a family history of colon cancer in a first degree relative doubles your risk of getting colon cancer,” said Klapman. “The lifetime risk for the average person is 4%. If you have more than one first degree relative affected, your risk increases even more.”

Following his surgery, Mancini finished chemotherapy in November and has since been declared cancer free. He rejoined his teammates for spring training in February.

“There were times early on when I wasn’t entirely sure I’d be playing baseball again,” Mancini said. “I’d be lying if I’d say that was the first thing that came to mind. The whole time I just wanted to be healthy long term and live a long life. And baseball definitely was on the back burner when I was going through all that.”