FORT WORTH (CBSDFW.COM) – Doctors say they still don’t know what caused Florida Gators basketball star Keyontae Johnson to collapse on the court unconscious last week.

The Associated Press reported the 21-year-old had tested positive for Covid-19 in the summer.

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While doctors don’t know if Johnson’s collapse had anything to do with the virus, doctors for months have raised concerns about Covid-19-positive athletes return to play protocols.

Florida Gators forward Keyontae Johnson (11) looks on during the Florida Gators game versus the Utah State Aggies on December 21, 2019 at the BB&T Center in Sunrise, FL. (Photo by Mary Holt/Icon Sportswire via Getty Images)

In some cases, the virus has been known to cause inflammation of the heart muscle which can be deadly if ignored, especially in athletes because of their enhanced level of activity.

Raul Chavez was a healthy college freshman who got a scholarship to play his favorite sport at the University of Dubuque in Iowa.

“He played soccer and he was tackling the guys up” said mom Tanya Lenser. “They said oh! He’s a football player!”

From a very young age, the athletic Chavez knew he loved football.

But then, in September he was infected by the virus when in college.

“I had like over a 103 fever,” he said. “I was just in my room in my bed shivering but i was sweating and had a throw up bucket right next to my bed.”

Raul Chavez (credit: Baylor All Saints Fort Worth)

After recovery, he was eager to get back, but the university required blood work to clear him for play.

The labs came back with high troponin levels indicating potential problems with the heart.

“They did an echocardiogram just to be safe and they said, yeah there’s some thing in here that’s not supposed to be there,” he said.

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The doctors wanted him to get admitted to a hospital there but his mother got him back to Fort Worth.

They consulted Dr. Farhan Ali interventional cardiologist at the Baylor Scott & White All Saints Medical Center.

“When I saw the echo from Iowa, I was really immediately concerned,” he said. “It was a clot of blood clot that had formed as a result of a complication from associated with the Covid virus.”

Chavez had a big clot in his left ventricle which was swirling in the chamber. Doctors say a clot in the heart chamber can be a dangerous condition that could cause stroke or even death if it is dislodge. Raul was hospitalized and on medication to reduce the clot.

Dr. Ali says – Chavez suffered from myocarditis—an inflammation of the heart muscle- which can weaken the beating of the heart.

According to one report, approximately 7% of the deaths from Covid-19 can be attributed to complications from myocarditis.

“It was a little alarming that he’s basically a ticking time bomb and that thing could dislodge,” mother Tanya Lenser said

The good news is the medication Chavez is on is working. But the once active football player isn’t allowed any strenous activity for the time being.

He never imagined the virus would touch his heart on and off the field the way it has.

While it is rare, doctors say it is often missed.

The American College of Cardiology is urging schools and colleges to perform heart screening on all athletes, sick with Covid-19 before clearing them for play… so that they are able to catch complications like that in Chavez’s heart.

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