Why is warming up a pitcher so random?

[Chuck_Dizzle29_PSN]

In a BR game I'm hitting in the bottom of the 2nd so I select Diego Castillo to warm up. This is my second game and he has not pitched yet in a game. Before the inning ends I check and he's at 98% warm. I select ready and waiting, then select to out him in the game. I fly out to end the inning and Castillo comes in... with a yellow bar to start.

If course I get a K and then give up three straight late bloops to load the bases. In a panic he has two diamond lefty hitters coming up. I select to warm up Rookie John Franco. I do a mound visit to get him maybe 30% warmed up. He comes in with a green bar and I get a double play to end it.

Why when I do what I'm supposed to do does my RP come in shot, but when I panic warm up a RP does he come out locked and loaded? Can we just turn it off, I don't understand how this can be so goofed.