Organized by alphabetical order in the title to prevent an indication of preference at this point.
There has been speculation that the Brewers will sign one of these pitchers to fill out the rotation. Realistically, they all would make the team better by a win or even two depending on who is bumped from the rotation. These three have all been very close to exactly average pitchers over the past three years, producing about 2 wins above replacement level per season.
Here's a quick look at some of their numbers. The CHONE projections are first, and the progression of FIP from '07, '08, and '09 are in parentheses.
Davis: 4.41 FIP, 6.25: 4.37 k/bb ratio and 44.6 GB %; (Last 3 years: 4.72, 4.15, 4.84)
Garland: 4.72 FIP, 4.55: 2.71 k/bb ratio and 46.3 GB %; (Last 3 years: 4.36, 4.76, 4.48)
Washburn: 4.73 FIP, 5.28: 2.96 k/bb ratio and 36.2 GB %; (Last 3 years: 4.77, 4.72, 4.58)
It's pretty tough to pick out the best option out of the three of these. They're pretty much equal in terms of projected performance for next year. I tend to be biased towards pitchers with higher strikeout rates, but I can also see the argument for Garland based on durability and ability to throw with the right hand.
Garland, though, just strikes me as a bad idea. First of all, his projected line looks a lot like Braden Looper's did last year, and looks a lot like Looper's does this year, for that matter. We saw first-hand last year what happens when a low strikeout, low walk pitcher happens to start giving up home runs. There's also this, from Ennder at Brewerfan.net:
Garland age 26-29. 129 GS, 820.1 IP, 1.40 WHIP, 409 K, 218 BB, 91 HR, 4.41 ERA
Suppan age 26-29. 129 GS, 818.1 IP, 1.37 WHIP, 449 K, 258 BB, 106 HR, 4.52 ERA
So generally I would prefer Davis or Wasburn. Don't let the projected FIP difference throw you off too much, they're about equals in terms of skill. It wouldn't be a bad idea for the Brewers to get one of these guys on a 1-year deal to finish out their budget, and it's too bad they had to throw $3.5 million at Latroy Hawkins. A one-year deal for Washburn at $6 or $7 million would be tough to complain about, but we have no idea if it's out of the Brewers' budget.
If Washburn does sign with the Twins, Melvin would probably be wise to investigate a trade for one of their younger excess starters. We'll assess that situation when Washburn decides where to sign, which will likely be soon.