If you told me to guess the first two pitchers injured in spring, DL & JB would have been near the top of the list, so as much as it sucks for them they were both already kind of in the anything you get is a bonus camp for me anyway.
Peralta, Nestor, Tobias, and Civale are a fine first four. Obviously the fifth spot is a little murky at this point but can't do much better than someone with Ashby's upside as a place holder until Woodruff is ready. Gasser should be coming at some point later in the summer too. The AAA rotation of Misio, Henderson, Patrick, Carlos Rodriguez, KC Hunt has five prospects with varying degrees of performance and potential under their belts.
Megill, Payamps, Koenig, Hudson, Peguero, Mears, Alexander and R5 Connor Thomas is a pretty deep and intriguing MLB pen with guys like Yoho, Uribe, Elvin Rodriguez, the two Grants that got 40 Manned, and Deivi Garcia providing another half dozen or so options.
If the Brewers front office and pitching dev braintrust like one of the guys still out there, sure go ahead and sign em up, but I don't think the Brewers have any urgent need to address things as they stand.