MLB proposed a way to reduce the use of relief pitchers:

Major League Baseball has proposed going back to a 15-day disabled list and increasing the time optioned players usually must spend in the minor leagues, a person familiar with the negotiations tells The Associated Press, moves aimed at reducing the use of relief pitchers and reviving offense.

The person spoke on condition of anonymity Wednesday because the plans were not publicly announced.

The minimum length of time an injured player spends on the disabled list was cut from 15 days to 10 in 2016 as part of baseball’s new labor contract. As a result, DL placements rose from 563 in 2016 to 702 in 2017 and then again to 737 last year, the commissioner’s office said.

StarTribune.com

If I remember correctly, the idea behind the shorter disabled list was the protect the health of the players. Rather than keep someone playing due to a minor injury, the player could go on the disabled list for a short time, heal, and be back quickly. Not surprisingly, the rule was manipulated in a way that was not expected.

My guess is that the new rule will help a bit in the short term, but it’s clear that MLB keeps moving toward a model where pitchers throw as few pitches as possible in a game, but appear in a lot more games. Allowing fewer pitchers on the roster will simply mean that fewer pitchers will be used as starters, and we could see the opener, long reliever, series of closers model adopted everywhere. Instead of five starters, there would be three long relievers and nine other pitchers.

My guess is the union does not agree to the rule change, anyway. The rule would lead to fewer players earning major league money during the year, and that’s will not be allowed.