First off, this is simply speculation based off an article I read this morning. But looking more into I see some positives that could come to light.
The Brewers have recently requested to review the contract of a current SS on the Texas Rangers by the name of Elvis Andrus. Andrus, 23, is currently in his third season with the Rangers and would be under club control for another 3 seasons. In that article it stated that in addition to Greinke, a position player and a relief pitcher would be included for Andrus, touted prospect Martin Perez and a lower level prospect. If this trade were to occur the 2013 roster/lineup may look a lot more promising than first thought.
Before I talk about the lineup, I must state my belief that Zack Greinke may in fact resign with the Milwaukee Brewers in 2013. Based on the removal of salary from Marcum, Wolf, and Rodriguez, the Brewers may have enough salary space to offer Greinke 5 years at 22 million. This would put the Brewers back near 90 million while controlling a majority of their roster for the next 3 years.
SS Elvis Andrus
CF Carlos Gomez
LF Ryan Braun
1B Corey Hart - Mentioned as proposed position player. Mat Gamel would then take over and hit 7th or 8th in this lineup
C Jonathon Lucroy
2B Rickie Weeks
INF Jeff Bianchi
INF Alex Gonzalez
3B/1B Mat Gamel or Nyjer Morgan OF
3. Martin Perez
4. Mike Fiers
Peralta/Thornburg/Narveson/Loe Possible Veteran addition
The roster above is very promising. With the additional resigning of Alex Gonzalez as a RH bench bat and backup infielder the Brewers would have a better RH Bench Bat than they currently have this year. . His value has dramatically decreased this year and the Brewers have a 4th outfielder who can play multiple OF spots in AAA in Logan Schafer. All in all, the Brewers bullpen should have a bounce back year but also shows a removal of replacement level arms of Hernandez, Dillard, McClendon, Loe, and K-Rod.
Also if Greinke were not to sign, the Brewers would then look to probably resign Marcum or give Peralta/Estrada another chance at a rotation spot leaving the Brewers a little thin in the middle of the rotation.
All in all if the Brewers were to go through with the trade I read on MLBlogs this morning, later removed, they should be able to compete next year and in 2014 as well.