Jim Furtado at BBTF links to this story about how Dave Stewart believes the Diamondbacks pitching staff is underachieving. Furtado quotes Patrick Corbin:

Frustrations ran high on Friday night, with Corbin complaining that the coaching staff doesn’t show enough trust in the rotation.

Corbin said that after giving up a leadoff double in the seventh – the first hit he’d allowed after retiring 11 in a row – he saw the bullpen begin to stir and felt he needed to make perfect pitches to remain in the game. He wound up walking a the Nos. 7 and 8 hitters and giving way to Clippard, who gave up a grand slam to the Marlins’ Justin Bour.

“You just want some trust in you,” Corbin said. “Maybe show some trust in the starter that they can work their way out of that.”

And comments:

If seeing a reliever stir in the pen bothers you, the coaching staff isn’t the problem.

Yes and no. The research suggests pitcher do worse every time they go through the order, and by the third time through managers need to be looking for trouble. I would guess for most pitchers it’s better to get the bullpen in sooner than later. It strikes me CC Sabathia owes his good ERA this season to the Yankees getting him out of games before he gets in trouble.

So the bullpen should be getting up when Corbin gives up a hit in the seventh. In fact they should probably be warming up before the inning starts. It is up to the coaching staff, however, to communicate this to the pitcher. Make sure the pitcher is aware of the third time through the order weakness, and know that getting him out is for the good of the team, not for a lack of trust. Corbin is seeing the bullpen getting ready as a sign of failure. The coaching staff needs to persuade him that this is a positive, that every batter he faces the third time through the order is a win.

(Maybe the right person to do this is Zack Greinke. Over the years, Greinke shows a very good understanding of sabermetrics. It might mean more coming from him.)