If you are in a franchise or season mode and you have a tired player and
u need him to be fine and  not tired for his health (like Griffey Jr.
because he always gets injured) go to your season/franchise Menu page
(If you are confused about where your franchise page is, look at the top
black line and it should read (FRANCHISE MENU) and go to setup, then
edit rosters. Now go to your team and highlight who you need to be fine
and press X. A list comes up and go to edit player. If you don't want to
change a thing just press start through the player editor screens. After
that, your player will be as good as new. This is really useful if you
have a player that gets injured very easily. This code DOES NOT work if
the player is already injured though.