Weak Bullpen and Weak in Center Field.
Their starters, though not weak, are worse than the D-back starters, which will put pressure on their bullpen. Their bullpen is below average in the Majors. Even if the Brewers take a lead, the D-backs will have a good chance to comeback.
Keon Broxton is the primary center fielder for the Brewers. As I write this, he has the exact same OPS+ as Nick Ahmed (92). On 5 June, the Brewers called up a top prospect Brett Phillips, who played a game at center field. In his first three plate appearances, he got a single and two strikeouts.