When Brian Wilson went out for the year early in the 2012 season, Bruce Bochy said he'd roll with a closer-by-committee approach. Santiago Casilla would be the primary member of that committee, and he did so well in the early going that Bochy basically made him the closer.
Things have ... changed.
Casilla, who surrendered just three earned runs through the month of May, has given up 10 earned runs in his last seven innings and has blown four saves in six appearances in the month of July. Fortunately for Casilla, the Giants have won two of those, with the latest a crazy 9-4 win over the Braves that has Bochy pondering a change.
“Whether we make an adjustment or not, I can’t answer that now,” Bochy said. “But there comes a time with every player when you have to change it up. I don’t want him to lose confidence.”
It's entirely possible that Casilla is suffering from the dreaded "closer's mentality," in which things happen to a pitcher during the final inning that can't be explained by simple stats or injury or whatever else might be an actual reason. Unless you count something like anxiety anyway.
“Casilla just got away from pitching a little bit,” Bochy said. “He’s too good to do that tonight. … He gets a little anxious there with the last out. We’ve seen that a few times. There are some good hitters up there and he’s trying to power his way through them.”
This is a pretty good explanation from Boch here: take a look at Casilla's stats and you can see his strikeouts-per-nine innings ratio has spiked since he started coughing up saves. Typically you want a high K rate (duh), but lots of K's can mean he's trying to overpower hitters.
It can also indicate he's facing too many hitters. That's quite clearly the case, since Casilla's not locking down many saves these days. And it means he's gotta tighten up the ship, or else someone like Sergio Romo -- or an outsider -- could end up getting a look as closer.