My vaccine passport also has my positive diagnosis date on there so you’re quite right. Obviously depends on you having had a formal PCR test as that automatically feeds back to the NHS.
The turnstile light flashes orange when a kids ST is scanned. It’s only a problem if the steward on watch clocks it. A mate used my daughter’s ticket for the Blues game and sailed through as the steward was looking away. Pot luck really.
No idea on the nature of the injury. But if there is no fracture or obvious signs of severe bruising/swelling I suppose you have to rely on the player to an extent? Not sure if they’d MRI scan for a fairly impact type injury?! Maybe they would.