Nerds like tec do.    He also has a pocketful of these:

A lot depends on your medical budget(for recovery because it doesn't stop injuries), your depth and how good the player is.    The better the player, the less I worry about his health.  The better the back-up, the less I worry about health.   And, because I have 20m in medical, the player and the back-up are key to me.  While many will argue that health doesn't matter because "it seems like 90 health guys get hurt as often as 30 health guys", it does matter.   I don't sweat 70 health very much but, when you drop into the 30s, it's not a matter of "if", it's "when".   If I didn't have a good back-up and high medical, I'd probably be OK with a couple of players in the 50s but would look to fill my team with 80+.