Yes I can fully understand how painful it could be to have a split fingernail, and in the way a pitcher must hold the ball, would be painful to do so.

Are we supposed to feel sorry for them? Either he can alter his pitch for the time being, or he can suck up the pain. I don't think that there would be any permanent damage to alter his pitch. And yes I know it's just like golfing, it may be hard to change a swing. But hey if you make enough money, then suck it up.
Take him out if he can't pitch properly, but don't make me feel sorry for him.

In football, players who are hurt, either play hurt, or are taken out of the game, and little johnny is right there behind him playing his position, just as well.
I find that baseball players seem to be glorified a bit too much. Like when there was a comment once about Cal Ripken having to go from shortstop to third base, and how difficult it would be for him to make that transition.
Honestly I don't follow baseball much, but is it really that hard to play another position?