Minor League Baseball announced a slew of major changes to the game the biggest of which is placing a runner on second base at the start of extra innings. It was a move to both speed up the game, as well as protect young athletes who have already played 9+ innings of baseball. It was a possible rule that Rob Manfred talked about this off-season about possibly implanting in the big leagues, however it was ultimately decided against and instead will be used in the minors.
A second rule announced is number of mound visits allowed by the manager over the course of the game.