Jason Giambi is no first baseman. He never has been a first baseman, at least,
not in the sense that you mean. So as Giambi's offense declined with his steroid usage, he became even more of a liability at first -- how can you justify playing someone who no longer generates his offense?
Anyway, Giambi's offense will likely bounce back, and this year he's -- don't look now -- maybe not an absolute siv at first.
Quoth the Tino:
"He's actually moving around better than I thought," Martinez said. "I think he was feeling tentative in the past. The whole key is moving your feet but not being afraid to make a mistake. You don't want to hold the ball when you got an easy out at second and just get the guy at first. In the past he would do that. Now he's not afraid to go and get lead runners. That really helps the pitching staff."
"I'm excited to play defense," Giambi said. "I hate DH-ing. It's too boring; I want to be part of the club. I can be part of the team, I like being on the field."
If the Yankees can get even passable defense from Giambi at first, they can put their best offensive lineup on the card, and for the Yankees "best offensive lineup" equates roughly to "oh my god they're all monsters." We'll see if Giambi's defense is more than everyone making Jason feel better about himself, though. After all, A-Rod says nice things about everyone.