In short, Gary Sheffield is having himself a good old fashioned Gary Sheffield tantrum full of empty threat-type statements and dickhead posturing because he's been told that the Yankees are going to pick up his option, then likely will trade him. He now does not want to play first base (maybe being so bad at it swayed his willingness to give it the ol' college try), and picking up the option allows the Yankees to control Sheffield's destiny, which means he can't sign with the Red Sox, which has been the rumor for a while.
What the hell is he going to do, beat up George Steinbrenner? Chokeslam Brian Cashman? Refuse to play for the team he's traded to? Or will he just piss and moan in typical old timey Sheffield fashion?
I was hoodwinked when I defended Sheffield toward the end of the year and said I wouldn't mind having him on my team. I still wouldn't, but not if he's going to be a baby about it. It's not even that I don't get why he'd be frustrated by it, but maybe just shut up for once ever, dude. He's a hell of a player, but what an annoying human being.