Apparently the Brewers are pushing Peralta to the Cubs series and using a bullpen game vs the Reds. This is a double whammy for the Cubs, 1) giving the Reds an easier game to potentially win in the Brewers series (though lol at the thought of the Brewers losing a baseball game) and 2) pitting Peralta vs the Cubs when he was scheduled to miss the series (though the Cubs handled him pretty well last time).
On the positive side, a bullpen game the day before a doubleheader vs the Cubs seems like a good thing.