Let's be honest, the Brewers really need to start being better on defense if they're going to overtake the Dodgers and win a World Series, as they're highly unlikely to be able to outslug the Dodgers.
Pratt's callup and the presumed removal of Rengifo from the roster (not to mention the likely end of Hamilton's time at SS) should be a major boost in that department irrespective of his ultimate offensive production.
The next logical area of defensive improvement is CF, where the Brewers could potentially be getting GG (even if not-PCA level) production from Luis Lara. If I were the Brewers, I would seriously explore moving Mitchell to RF in favor of Lara and then Chourio (who has been better than Mitchell in the this OF per the metrics) when Lara isn't in the lineup.