First off “football” in this context is soccer, not American football, but here are the stats for 2021:
353 unusual health events among athletes total (so far, at least the ones who made the news) for 2021 (from age 16-53). 238 of these events occurred in athletes 35 and younger. 146 aged 25 and under, and 93 were aged 20 and under.
177 collapses during practice, training, game, or immediately after
167 heart related events (107 heart attacks, 12 myocarditis, 7 pericarditis, 5 arrhythmia)
Other events: 13 clots, 9 strokes, 4 seizures
192 total deaths
130 unusual Soccer events including: - 89 collapses during game or training - 80 are under the age of 25 - 72 mention heart issues (46 cardiac arrest, 3 arrhythmia, 5 myocarditis/pericarditis) - 62 deaths (39 deaths age 30 and under)
30 unusual Football health events including: - 21 younger than 20 - 22 deaths - 16 collapses happened during games or training - 7 cardiac-related, 3 seizure-related
26 unusual Running/track related events: - 17 deaths - 14 cardiac events - 17 happened during training or in races/meets
https://freerepublic.com/focus/chat/3988541/posts?page=357#357
And - a footnote to my post above,
I did NOT include events related to injury, heatstroke, concussion, etc.