Denver Broncos linebacker Alex Singleton is opening up on his recent testicular cancer diagnosis, which he received by way of a random mandatory NFL drug test.

“I’m happy I’ve had this positive outlook through it, because it has been so fast,” said Singleton, reflecting on the diagnosis in an exclusive interview with “Good Morning America’s” Trevor Ault airing Tuesday.

Singleton, a team captain for the Denver Broncos, was diagnosed with testicular cancer following an NFL-mandated drug test earlier this season.

After the Broncos took on the Dallas Cowboys on Oct. 26, Singleton said he found an envelope in his locker, indicating he had failed the drug test.

“All I see is what the hormone was,” he said, remembering reading the letter that delivered the news. Upon researching the detected hormone, human chorionic gonadotropin (hCG), Singleton said he came to realize, “If it’s in a male, pretty much you’re either injecting something or you have testicular cancer. And I’m like. Neither of those makes sense for me, so then I was just super confused.”

Singleton described laying out the two possibilities in front of him: one, a possible suspension for breaking the rules, and the other, battling cancer.

On his wife’s suggestion, Singleton scheduled a urologist appointment. “It was kind of just like, all right, try not to think about this for the next 72 hours and go play an NFL football game on Sunday and be ready to go to this doc on Monday.”

Singleton would take the field for the Broncos on Sunday, as they played the Houston Texans on Nov. 2.

“I thought about it 24/7,” he said. With the pressure mounting internally, Singleton recorded 10 total tackles in the Broncos’ win.

After meeting with a doctor and taking an ultrasound, Singleton confirmed his testicular cancer diagnosis by Monday night and had surgery scheduled for Friday.

The night before the surgery, Singleton elected to play in the Broncos’ Thursday night matchup versus the Raiders.

“I just want to play football. If this is the last time I get to play football like that’s what I wanna do,” he said, describing his mindset. He would go on to play all 60 defensive snaps for the Broncos.

The next day, Singleton went in for surgery.

The operation was ultimately a success, and a CT scan showed the cancer had not spread.

After the surgery, Singleton opened up to his teammates, sharing the harrowing experience with them.

“I’ve learned more in this past week just of compassion and empathy through a bunch of tough dudes than, you know, anything else I think I’ve ever gone through,” he said.

Beyond his teammates, Singleton says he’s gained a new appreciation for his support system at home: his wife, young daughter, the team’s ownership and medical staff.

Singleton also said he now appreciates the importance of being proactive when it comes to one’s health.

“I don’t like goin’ to the doctor,” said Singleton, who added that through this experience he’s learned “how quick it is, how easy it is and how detectable it is through that.”

“I want to be the guy that’s staying on the top of every mountain just going, ‘Get this done,'” he said.

Singleton’s recovery has moved at a rapid pace. He’s only missed one game and is hoping to return this Sunday when the Broncos take on the Washington Commanders, less than one month after his cancer diagnosis.

According to the National Cancer Institute, testicular cancer is “a disease in which malignant (cancer) cells form in the tissues of one or both testicles.” Testicular cancer is rare and “is most frequently diagnosed in men ages 20 to 34,” the agency states.

Treatment for testicular cancer can include surgery, radiation therapy, chemotherapy, surveillance and high-dose chemotherapy with stem cell transplant, according to the National Cancer Institute, which notes that testicular cancer can come back even after it has been treated.

Men with a history of testicular cancer “have an increased risk of developing cancer in the other testicle,” according to the National Cancer Institute. Patients are advised to frequently follow up with their doctor and regularly check both testicles even after completion of treatment.