What bothers me is that the Brewers are prioritizing the bullpen over the starting rotation. The team has set the 2013 payroll budget at 80 million. Right now payroll is projected at ~75 million. So they have 5 million left to sign a starter, assuming the bench spots are filled with major league minimum guys.
Right now, I don't think there's anyone left who would take 5 million, who would be worth adding, unless that's enough for Marcum. Most of the low cost, high upside pitchers (McCarthy, Feldman, Baker, etc.) have already signed. So it looks like the Brewers will be filling the rotation with internal options.
The current rotation candidates are: Gallardo, Estrada (these two are guaranteed a spot barring injury), Fiers, Peralta, Rogers, Thornburg, Narveson. Not a very exciting group of players. There's some potential with some of the prospects in that group, but counting on them to give you 30 starts/200 IP is foolish. On the other hand, counting on those players to transition to the ML level by taking a bullpen spot in 2013 is a lot less riskier. However it looks like the bullpen is almost full with established relievers at this point. Just odd roster construction in my opinion.