Spring training preview, Part II: Projecting an improving rotation, bullpen

JT Brubaker.The Pirates' spring training is set to open Wednesday in Bradenton, Fla., with the first formal workout for pitchers and catchers.

To build up toward the start of another season, we will be projecting the potential opening day lineup, rotation and bullpen. Today, we're looking at the pitching side. The Pirates went into this offseason looking to get more whiffs out of the bullpen and improve the rotation. Did they accomplish that?

THE OPENING DAY ROTATION

1. MITCH KELLER

Keller rediscovered his mojo and his fastball velocity last winter, and after a stumble out of the gate, became the Pirates' best starter down the stretch. He's bringing back the gyro slider (closer to a cutter) he…