Yesterday Joe Sheehan wrote in his newsletter (which I recommend subscribing to) that the Royals should go after Edwin Jackson. Sheehan is and has been a Jackson advocate, pointing out that over the last three years, he's been very effective. For whatever reason, he's the rare example of the demand for a player not having a recency bias.
Since being traded to the Tigers, Jackson has made 96 starts, posted a 108 ERA+ and struck out 7.1 per nine. Next season will be his age 28 season, so he still has some upside.
As Sheehan points out, there aren't many teams left for Jackson to sign with and the Royals should be in that group.
The weakest link on the Royals is a starting rotation that, while improved, is loaded with back-rotation types like Bruce Chen and Luke Hochevar. The Royals don't need starts; they need a starting pitcher, and if signing Jackson means Danny Duffy goes back to Triple-A or Luis Mendoza starts the year as a long man, neither of those is that bad relative to the three- or four-win upgrade Jackson represents over those two and the other in-house options. Adding Jackson makes managing the staff easier, thanks to his reliability, and because Jackson is 28 and improving, he even brings some upside. The Royals don't catch the Tigers by signing Jackson. However, the move would close the gap between the teams and make it more likely that an upset would happen. It also starts to position the team for 2013, which should be their year to win.
It's hard to know just what exactly the market for Jackson now is. Sheehan threw out Buerhle's contract as a possible comp -- 4 years $58 million -- which is as good as guess as any. The Red Sox are still out there as possible rivals, the most likely big market team that should be interested. According to internet rumors, Jackson has multiple three-year offers before him. Could the patented Dayton Moore extra year be enough to sign Jackson?