4. RHP Joe Ross
The Brewers signed free agent veteran Joe Ross to a major league deal this offseason to help address the pitching depth shortage. Milwaukee hasn't done much else to address that depth problem to this point and Ross currently is slotted as the No. 5 starter in the rotation. However, it'd be a little surprising if Ross is still in the rotation come the end of the season.
Ross hasn't pitched in the big leagues in two years and while the Brewers believe he's good to go, his performance simply may not be up to snuff. At the same time, the Brewers are loaded with pitching prospects in the upper minors that are just about ready to take over spots in the rotation but not ready enough for the Brewers to go into the season with them in the starting five.
Ross' deal is cheap enough that the Brewers can move on without a second thought if he struggles and the kids prove they're ready for an opportunity. Robert Gasser, Carlos F. Rodriguez, and Jacob Misiorowski all could earn big league innings this year in that rotation. They're the future of that group and Milwaukee will want to give them opportunities. Those opportunities won't come at the expense of a Burnes, Peralta, or Miley though, they'll come at the expense of someone like Ross, especially if he struggles.
While Ross could be pushed to a bullpen or swingman role, the roster churn has the potential to cost Ross his spot eventually. If the Brewers add another starting pitcher this offseason, Ross is already on the outside looking in for this rotation and is teetering on the back end of the roster. Without minor league options, any struggle could lead to a DFA so the Brewers can bring up a young arm that still has options.
Ross hasn't had a sub-4.00 ERA since 2016 and if that trend continues, there will come a point in the season where the roster math does not work out in Ross' favor.