It really wouldn't be that hard. MLB struggles with it because they actually have to deal with travel, etc. For The Show they could just come up with some simple parameters and weave them in.
If a rain out occurs early in a series, make the following day be a double header. If it's the last game of a series, make it a double header the next time the two teams play. If the two teams are done playing each other for the year push it ahead to the next time there's an off day for both teams. If both teams have already been eliminated and it's late in the season, cancel the game. If the game needs to be played at the end of the year do it then.
Compared to some of the other stuff that goes on with coding this would be relatively simple.