I actually would say Skulina, give his age and college experience. Tseng probably would handle it the best, but I doubt they want to move him. There's also James Pugliese, who's dominated out of the pen all year.
Nah, they wouldn't screw with someone who has a future with the team like that. I'm worried he's injured. Didn't they hold Rizzo down for months when he was more than ready at AAA? Kinda apples and oranges with your franchise player and a late-inning reliever, no?
There's also xFIP, which is basically the same thing, but instead of using HR the pitcher has allowed, it uses how many HR the pitcher should have allowed.