When a bloke comes off the ground and points to his foot knowing he has already injured it similarly before and your club says it's an ankle injury and then takes another three or more weeks to realise it was the foot injury he noted himself and not the ankle at all, that's not good.
If a player spends a complete season in rehab with a knee injury, is then delisted, then goes to a WAFL club who fix it in the off season, so much so that he is redrafted by another club, something's wrong.
If someone has an endless recurring injury that sees him only play two games in 4? years, leaves the club and finds a specialist a week later that operates on him successfully enough that other clubs are enquiring about him and looking at picking him up for nothing next year, changes are needed.