He hasn’t abandoned his bread-and-butter curveball (yet), but Barry Zito, the Giants’ prized off-season acquisition, has tweaked his delivery, much to the concern of pitching coach Dave Righetti.

Apparently, Zito wants to generate more power from his lower body, a focus of his off-season training.

From the jail-free San Francisco Chronicle:

The idea is to generate more thrust with his legs and less with his arm, which not only should preserve the arm and allow him to throw more innings, but also create later and more powerful movement on his pitches, including the fastball and curveball.”I just felt constricted, really, the last few years, like I was throwing all arm,” Zito said, “so it’s about using the core of your body, the center of your mass, instead of your arm.”

Zito has changed his workout regimen this winter to strengthen his legs and hips, so the new delivery goes hand-in-hand. Actually, he called it an old delivery he used in college.

Righetti is not thrilled with the idea:

“It’s going to change the flight of his ball,” Righetti said, suggesting Zito could lose his signature curveball. That is why Righetti said “yes” when asked if this was worrisome and “I don’t know” when asked if he might try to talk Zito out of it – something Righetti would not do until he sees how well Zito progresses over the next few weeks.

Surely, this is a pre-emptive move on the part of the guitar-slinging Zito, still waiting for that call to go on tour with Dave Matthews Band. Better he change his delivery than try his hand at Guitar Hero.