Oh, he must have gotten vaccinated!
Both were unvaccinated. COVID-19 causes myocarditis, and it does so at a higher rate than the vaccines. Regardless of vaccination status, people involved in high endurance/intensity sports should probably get screened. Teams should be offering/requiring it to protect their athletes.
I've also read several doctors warning against high intensity activities for several weeks after COVID or vaccination, as it can exacerbate the inflammation.