Not a doctor but I don’t think that’s the case for sure, depending on the diagnosis. If it was some type of heart defect, likely yes. If it was the impact stopping his heart, that’s more of a freak incident (how many times had that happening in the NFL in the past 25 years?). I don’t know if having it happen once increases the likelihood of it reoccurring, but it’s not like a knee or neck/back injury that impacts your ability to move on the field. It’s not unreasonable to think a 24 y.o. professional athlete has a reasonable chance of playing again (assuming that they aren’t at a risk for reoccurrence. At the same time, no one would blame him for walking away either.