IF (4/5) - Victor Martinez may be moving to 1B. I guess it comes down to who has a better Spring out of Shoppach and Garko, because one of those will have to sit. DeRosa is an excellent player who can play pretty much any position well. With Peralta and Hafner at SS and DH, that leaves Marte as the only question mark. But there should be plenty of flexibility with DeRosa around, and possibly Tony Graffanino now as well.
OF (4/5) - The three starters are solid and Dellucci is a good veteran back-up (though his average has dropped lately).
SP (3/5) - Lee was the best pitcher in the league last year, but he's the only one locked into a spot. Carmona and Reyes have looked good and should be 2-3. If Pavano pitches like he can, that'd be a good #4. Potential to be a good rotation.
RP (4.5/5) - Kerry Wood had a great year. Perez, Lewis, and Smith looked good last year, as did Kobayashi, through June at least. Betancourt can do better and likely will. Meloan and Miller will try to win a spot. This can be a great bullpen when healthy, assuming the starters aren't giving them too much work.
Wildcards: Trevor Crowe, Marte, Jake Westbrook
Can they beat the Brewers? Yes.
[Disclaimer: I do not claim to be an expert on your team. I think it's fun to do this stuff before a season starts and then see how close (or how far off) I was. If you spend time from your day insulting us, telling others to insult us, or posting in a blog or messageboard about how wrong our opinions are, then we are flattered!]