2. LHP Sean Manaea
The only left-hander here on the rankings is the former Oakland A's, Padres and more recently San Francisco Giants pitcher Sean Manaea. Losing both Miley and Lauer leaves the Brewers without a starting left-hander and so this would be a position they need to fill.
Their fifth ranked prospect Robert Gasser fits the bill and is expected to come up sometime this season, but would it be too much too soon if he was relied on as the only left-hander in the rotation? Aaron Ashby is also making his return from injury and so he may be in a similar boat of being slowly integrated back in and may start out in the minors as he builds back up to full health.
Similar to Martinez, he can pitch out of the bullpen if required and that is of use to everyone. After a solid career in Oakland, his past two season have seen him put up ERAs of 4.96 and 4.44 which isn't going to blow anyone's socks off but can still be a nice option. Manaea can eat up innings which is something the Brewers will need.
Last season, Manaea was paid $10MM and would be worth around a similar price this offseason. He is definitely an option for the Brewers to look at to replace their losses of land-handed starters.