You don't have to sign a pitcher to a 1 year contract. Any return on a pitcher willing to sign a 1 year deal probably won't be very much anyway. A 2 or 3 year deal at a reasonable price wouldn't kill us. No reason you can't flip that player in the second or third year of the deal.
In the long run, signing a veteran inning eater may help us not be the laughing stock of baseball 3 years in a row. Theoretically it should help us avoid 4-30 stretches. Less innings out of our awesome bullpen. And it shouldn't jeopardize our top 5 draft pick.
Or we could sign a guy like McCarthy and hope he stays healthy so we could trade him for a couple of C prospects in A+ ball.