Some of David Price's peers have copied his unusual minimalist delivery in recent seasons, with the small steps seemingly designed to reduce extraneous movement and improve his command. But those pitchers will probably have to clarify their intent for umpires, just as Price has been asked to do by Major League Baseball, whenever there is a runner at third base.

Price was first informed about the umpires' concern in spring training of 2016, according to a source familiar with the conversations. A memo about his delivery and that of the Colorado Rockies' Chris Rusin was drawn up at that time, and as more pitchers have mimicked Price's delivery, the source indicates, the memo became a rule.

MLB's memo to Red Sox pitcher David Price two seasons ago has now become a rule requiring pitchers to alert umpires of their pitching delivery when a runner is on third base. Kim Klement/USA TODAY Sports

Price is not being asked to alter his mechanics, but because of the umpires' concerns about being properly able to identify whether he is working from a full windup or a set position, he will need to declare one way or the other. There are different rules in place for pitchers according to whether they are working from a full windup or from a set position.

The Red Sox pitcher first spoke about the scrutiny to his delivery Tuesday with WEEI.com. He told WEEI that he thinks the difference in his delivery from a windup or a set position is clear, but he has indicated he doesn't think this is a big deal at all.

According to the source, Price is not in any trouble. The umpires just need for him to indicate what he is doing with a runner at third.

The rule -- which could be called the Price Rule -- is detailed in this way: If a pitcher takes the rubber and his back foot is parallel to the mound and his other foot is in front, it is assumed he is in the set position and he will stop. This does not matter with no runners on or runners on first and second. But when there is a runner on third, pitchers need to inform the umpires if they are going to stand that way and not stop -- i.e., pitch out of the full windup.