The Reds-Cubs game tonight has been cancelled due to rain. The two teams have scheduled a split doublheader on Saturday, May 19th at 1:10 and 7:10 PM.
It was an interesting move not to try to play tomorrow, as there is little chance of rain most of the day. I am not entirely sure who gets to make that call, but if it is entirely on the Reds they might have decided they would rather play the Cubs when they have a healthier bullpen, and force the Cubs to possibly have to call up a starting pitcher just for the game.