Don Kelly is a utility guy... and Leyland used him way too much, even as a pinch hitter in game 4!
Delmon Young was another awful player. Didn't provide the power they thought, doesn't hit for average, and is probably the worst fielder in the league. Young is so bad the Phillies signed him for practically nothing. Berry also faltered down the stretch. He's no more than a fifth outfielder, mostly because of speed. They also have one of the worst fielding shortstops in Peralta. The guy is like a statue over there. Unless the ball is hit directly at him, he won't get it. Plus, he can't even hit anymore! Trust me... I know this team inside and out. I'm one of the few who followed them back when Randy Smith was GM and they were awful.
The Yankees always collapse (minus 2009). Part of it is the personalities not meshing. Part of it is managing. Part of it may be media pressures (which I think is a poor excuse, but some players seem to buy it). Part is also pitching- it always seems the back end of the rotation and parts of the bullpen are patchwork. There's also the very weak bench. If you are a Yankees fan, you should demand some change, but it looks like you are stuck with albatrosses such as A-Rod.