MVP Baseball 2004 Cheats

Cut him from the team. Then go to delete player. Then re-create him with the same name. He will keep his stats, but he will not be injured.

Pick your hitter or pitcher as normal, and set the difficulty to "MVP". Then start your matchup, and wait until each side (your side, and the CPU side) has had a pitch thrown and immediately go into the options menu and switch the difficulty back to "Rookie". You will play the rest of the matchup under that setting, but you will still get the points you would have gotten if you had played the entire matchup on the "MVP" difficulty.