In recent weeks, the Brewers have worked to rebuild their Triple-A outfield following the losses of Kentrail Davis, Caleb Gindl, Sean Halton, Jeremy Hermida, Kevin Mattison and Eugenio Velez. So far, the Brewers had picked up Matt Long, Ben Guez, and Bryan Petersen as potential replacements for the outgoing players.
On Tuesday, the Brewers brought in a fourth outfielder who will potentially see a lot of time at Triple-A Colorado Springs. Milwaukee claimed Shane Peterson off waivers from the Cubs, who had previously taken him off waivers from the Nationals. The move fills the Brewers' 40-man roster for now.
Peterson saw two games in the majors in 2013, but otherwise is a career minor leaguer. A 26-year-old left hander, he has spent most of his playing time in the corner outfield but also plays some first base. For his career, he has hit .284/.376/.421. He hit a career-high 12 home runs in 2013, so it's unreasonable to expect much in the way of power, though he did post a career-high 40 doubles this past season. Still, he has a good eye and has shown the ability to steal double-digit bases.
The Brewers had tried to claim Peterson when he was awarded to the Cubs, but ended up getting him anyway.
Importantly, the acquisition of Peterson means the Brewers have no more empty spots on their 40-man roster. Thus, in order to make a move for a major league player (bullpen help, perhaps), they will need to remove someone from that roster and potentially risk losing them on waivers.
Assuming that key players like Yovani Gallardo, Ryan Braun, Carlos Gomez, et. al. won't be removed, there are a few players who are more likely than others to be removed in the event of a new acquisition. Among those are:
Michael Blazek
Brooks Hall
David Goforth
Johnny Hellweg
Michael Strong
Taylor Jungmann
Juan Centeno
Hector Gomez
Yadiel Rivera
Matt Clark
as well as Peterson himself. Goforth, Jungmann, Rivera and Strong were all recently added to protect them from the Rule-5 draft -- if the Brewers were worried about them being chosen there, they may be unwilling to expose them by taking them off the 40-man and allowing a team to have a shot without needing to keep them on the MLB roster.
It's unlikely the Brewers' 40-man roster will remain as-is. As mentioned, they could use bullpen help in addition to potential upgrades on the bench. If they do sign someone to a major-league deal, they'll need to open one of those spots somehow.
For now, however, the 40-man is full as the Brewers continue to round out their minor league outfields.