I'll predict Wiemer makes OD roster.
Many of us were surprised when Mitchell came up last year, even though he was the chronological choice. Wiemer, too, is chronologically, the choice ahead of Frelick. In addition, he is the better defender, bats from the right side, offers more power, and is the baserunning equal.
We keep talking about what GMs do to manipulate service time, and maximize value, but we rarely give credence to the idea that GMs are usually judged by how effectively they help the team win.
Wiemer has yet to experience failure whilst healthy (or one could reasonably say so). Other than prospect lists, why wouldn't bullish Brewers fans like ourselves not consider him to not only be a superior prospect, but also the best current starting RFer in the organization?