If I was Terry Ryan, this is something I would look into. Trading Luis Castillo.
Don't get me wrong, Castillo did everything the Twins asked him to do this year coming over in the trade from Florida. Castillo was solid at the top of the order, getting on base, taking pitches, and playing decent defense at 2B. But at $5.75 million, he's become too expensive.
Consider, he's getting older, and his knees have been a problem for him, especially playing on turf half of his games. His game has always been predicated on speed, and he simply doesn't have as much of that as he used to, thanks to age and the chronic knee problems. There's also the matter of his defense. At one time he was a Gold Glover. That time has passed. He's not bad out there, but he simply doesn't have the range that he used to have.
And the reason we can trade him is that the Twins have other options. Mainly, two of them:
1) Alexi Casilla. The Twins got him in the JC Romero deal, and he's been superb. He looks like a younger Luis Castillo... not a lot of power, but a good eye, hits for a good average, plays good defense at 2B, and has great speed. However, he may not quite be ready to start in the Bigs, which is ok becuase we have...
2) Nick Punto. He was very good defensively at 3B, but his offensive production there is supbar. He played 2B when he was younger, and that might let him take more advantage of his very solid range.
Plus, we could use money freed up from getting rid of Luis Castillo's contract, Brad Radke's ending contract, etc. to go after a real 3B, of which there are some out there. This is basically a pipe dream, but I would pretty much be able to die happy if the Twins somehow got A-Rod, as Seth talked about a few days ago.
But anyway, there's no time like the present... Castillo's value probably won't ever be higher than it is now for the rest of his career. I hope this isn't all just a pipe dream.