The implementation of the DH could be offered to the Major League Baseball Player's Association as a way to employ more players, in return for some concessions from them regarding the schedule and other issues, according to mlb.com
Currently, only teams in the American League use the designated hitter. The term refers to a player whose only job in a game is to bat, not play defense. In essence, the designated hitter bats in place of the pitcher. In the National League, the pitcher is still required to take at-bats during games.
One of the proponents of the DH in the National League seems to be St. Louis Cardinals general manager John Mozeliak. He says there has been more talk and a shift about the idea recently. "I’m not suggesting you’re going to see a change but I definitely think the momentum (has changed),” said Mozeliak
However, MLB commissioner Rob Manfred is trying to put brakes on all the speculation. He thinks nothing will change in the foreseeable future. "I think the vast majority of clubs in the National League want to stay where they are," said Manfred during meetings with owners
The DH started to be used by the AL in 1973. Since then, NL owners have refused to consider it. This has led to slightly different styles and philosophies between the two leagues. In the past, teams from the AL and NL never played each other except for the World Series. Now teams play each other during the regular season as well. The DH rule is used depending on the home team.
Supporters of the DH say the position brings more offense and excitement to the sport, as pitchers are usually poor hitters. DH detractors suggest the position is one-dimensional and results in less strategies for managers during games.