The Next Bartolo Colon
From the likes of Wade Miller and Kyle Snyder to Bartolo Colon the Red Sox have often found value, or potential value in signing a veteran pitcher looking to right the ship after injury or at the end of their line to a one year deal and have them fill spots at the back of the rotation.
That type of insurance policy combined with an influx of youth at the tail end of your rotation has been invaluable in recent years where the Red Sox have needed their fair share of spot starts. I can remember more Julian Tavarez starts than I care to!
While the top of the rotation certainly is full of horses (Beckett, Lester, Matsuzaka) and Wakefield and the young guns (Buchholz, Bowden, Masterson) provide a solid tail, injury is unpredictable. The 2008 New York Yankees are a great proof to the theorem that you can't have enough starting pitching.