Wayne Sebastianelli was clear that B10 hasn't cardiac MRI'd every athlete who tested positive for Covid. However, among ones that were cardiac MRI'd (don't know number or why they were MRI'd) about 1/3 "had the level of inflammation that was determined to be myocarditis."

He acknowledged that some experts "feel this is a finding that is incidental and may not warrant any further investigation or concern. And they’ll let somebody compete again" after things clear up.

He said he didn't know of any comparable tests involving the flu, but said this is a different virus. Was very open about his uncertainty. He specially said there is a need for more study and testing to learn about this. It's a pretty nuanced and lengthy conversation.

This being Twitter, his comments were praised/condemned wholly. In truth, they are way more down the middle. This is a very reasonable person: "we really want to study this further to understand what is happening with the student athlete."

One more thing: it wasn’t a “study.” It appears he got this info somewhat informally from other athletic doctors from other schools, which may explain the rough numbers.