Let me say this first: I know this won't happen. The Yanks would never do this. But this is what I would do. This post is short and to the point.
The Yanks should forget Johan and Haren, trade Mussina for a prospect or bullpen arm, and sign Livan Hernandez. Why? It's pretty simple.
Livan had a very streaky year last year:
He walked way too many and got into alot of jams. Add the fact that that was in the NL and pitching in a great pitcher's park. But remember he pitched for a team that had a pretty bad offense. The high ERA was the effect of him either having control problems or leaving pitchers right down the middle. He was a middle of the rotation starter for the D-Backs last year. His career ERA is 4.25 which isn't great but it's by no means horrible.
The Yankees shouldn't trade for Johan or Haren. The Yankees have worked so hard rebuilding there young talent and keeping it. Trading for one of these guys might help them now but in the long run it might backfire horribly. Add the fact that the guys they trade will still be in the AL. I think if they would trade their young guys, they would rather trade them to the NL. The fact that Haren is gonna cost the same as Johan is ridiculous. Yes, Haren cost much less money but he's nowhere near the same type of pitcher Johan is.
Now Mussina. Mussina had a terrible year last year.
He had no movement on his pitches and no control. And since he has no speed, he has to have movement and control to win games. Without them, he's in trouble. And he had close to nothing last year. With that being said, I'm sure some team would want him for some little in return. Possibly an NL team. Maybe something with the Pirates. Say Mike Mussina for one of their bullpen arms the Yanks really want. The thing about Mussina is he wouldn't work in the bullpen. He's the kind of pitcher that the 1st inning is always the hardest for him. So for him to come out of the bullpen at anytime doesn't sound right. And I don't think he'll like it either. He could start for the Pirates and pitching in the NL should also help him alot in a contract year if he decides to try pitching again.
So you put all this together and this is what I get: The Yanks could trade Mussina for a prospect or bullpen arm. They gain something and open a rotation spot. Then you turn around and sign Hernandez. Make it a 1/2 year deal. The Yankees might have to pay a little extra for the short contract but they have the money. The reason why I want Livan is because he's a vet who will eat alot of innings and he'll be a nice back-end starter. Since the Yanks have alot of young pitchers that will need rest and probably some extra days off, you need an innings eater. Livan fits that role perfectly.
So that's my suggestion on what the Yanks should do. I know this will never happen but that's why I wrote this. I'm done.