There is "some belief" around the MLB that starting pitchers should be required to play a minimum of six innings before leaving the mound, according to ESPN's Jesse Rogers.
The MLB is the discussing the potential rule change as part of a goal to "restore the prestige of the starting pitcher," Rogers reported.
The league has discussed outliers to the potential rule, in which a pitcher could leave his start early, according to Rogers. Some proposed exceptions include the pitcher suffering an injury, or exceeding 100 pitches or four earned runs, per Rogers.
The new rule would require "years of advance notice" before it could be implemented in the MLB, Rogers noted.