Major League Baseball has made formal proposals to the players' union to bring about changes to both the strike zone and intentional walks, according to sources.

Neither of those innovations can be implemented without approval of the Major League Baseball Players Association. According to sources, the union is currently in the process of feeling out players on the proposed changes.

An agreement would have to be reached soon for the changes to take effect this season.

The proposal would raise the lower part of the strike zone to the top of the hitter's knees. Since 1996, the bottom of the zone has been defined as "the hollow beneath the kneecap."

The change in the intentional-walk rule would end the practice of requiring the pitcher to toss four soft pitches outside the strike zone. Instead, a team could just signify it wants to issue an intentional walk, and the hitter would be sent directly to first base.