Instead of another re-hash of "let's trade for Wandy Rodriguez" or "let's acquire whatever starting pitcher that MLB Trade Rumors mentioned today," something that might be worthwhile would be profiling pitchers who might be the next Felipe Paulino. These would be "failed" starters whose peripherals suggest that they are better than their ERA, injury reclamation projects, or relievers with underlying tools and skills that might translate to starting (e.g., some combination of good control and command, decent changeup or curve/splitter combo, low platoon splits).
These are guys that the Royals might actually be able to acquire without giving up a top prospect like Wil Myers or tie up the payroll through Hosmer's arbitration years. We have talked about Kris Medlen previously (injury reclamation project -- check, reliever who fits a starter's profile -- check), but there should be a good number of these guys out there. And again, these would not be guys who pitched well as starters in 2011 like Bud Norris who are considered "underrated" only because the national media has failed to talk him up.
Going through the Fangraphs leaderboards for relievers sorted by number of chanegups thrown, three relatively unheralded guys jumped out:
Atlanta right-handed journeyman reliever Christian Martinez: 6.72 K/9, 2.20 BB/9, 47.6% GB%, 3.72 FIP, 3.59 xFIP, 31% changeups.
A move from the bullpen and to the AL would reduce their expected numbers, but each would seem to have a fighting chance of posting a 2.0 K/BB and in the case of Estrada and Lopez, close to league average strikeout rates.
Obviously, these guys have some issues that led to them becoming relievers -- they are relatively short (~6 feet tall) and throw with averagish velocity (90-92 MPH as relievers, which would be expected to drop 1-2 MPH as starters). But while none are young (Estrada and Lopez turn 29 next July, Martinez turns 30 in spring training), it does not appear any of them are even arbitration eligible yet. Estrada is kind of a "name" reliever now, as is Lopez to a lesser degree, so their current teams would not give them away, but the fact that they are relievers should keep their asking prices reasonable.
I have not thoroughly researched each one, so one or all may not pan out upon closer inspection. If you have additional insights on these guys or other "next Felipe Paulino" candidates, please add them to the comments.