The minor league season will not start until the first week of May, but when it does start, there will be some rule changes implemented at various levels to allow MLB to observe the impact of those rule changes on the game.
At the AAA level, bases will be increased in size from 15 inches square to 18 inches square. This is done to reduce the chances of collision, though the announcement indicates the expectation is that the reduced distance between bases could result in a slight increase in hits and successful steals.
At AA, the defensive team must have at least four infielders, all of whom must have both feet in front of the outfield dirt boundary. This is to eliminate the positioning of the second baseman in shallow right field. In addition, depending on how that is evaluated, in the second half, there may be a rule adopted requiring the defense to have two infielders on either side of second base.
At high A, pitchers will be required to completely disengage from the rubber before throwing to a base, or else there will be a balk called. This is intended to increase stolen base attempts.
At low-A, pitchers will be limited to two step offs or pickoffs per at bat. If a third attempt is made, and the runner gets back safely, a balk will be called.
Also, in the Southeast low-A league, there will be an automated ball and strike calling system in place to “assist” umpires, and in the West low-A league there will be an on-field clock to enforce time limits for pitches, pitching changes and between inning breaks.