Do no harm: Who should bear the costs of retired NFL players’ medical bills?

you are assuming all taxpayers watch football. That is not a valid assumption. Maybe all fans are taxpayers, but not all taxpayers are fans.

Not only that, but a lot of people who work in an office all their lives have to get knee and hip replacements. It's part of the aging process.

That's why people work, and why they buy good health insurance. Since 1985, retired workers can choose to keep their employer's health insurance plan. All they have to do is keep up the payments. Anyone who would drop their health insurance is asking for it.