Source: MLB clarifies protocol

BOSTON -- It comes too late to save Seattle Mariners interim manager Robby Thompson, but according to an industry source, Major League Baseball sent a directive to all 30 clubs Monday, clarifying the protocol for signaling a change in pitchers, something that is not explicitly stated in the rulebook.

Thompson, who is filling in for Mariners manager Eric Wedge while he is recovering from a mild stroke, came out to the mound to make a pitching change in the bottom of the ninth inning Thursday night in Boston. Thompson pointed to the bullpen with his left hand, then tapped his right arm with his left hand, signaling his desire for right-handed pitcher Yoervis Medina.

But plate umpire Dustin Rackley, backed by crew chief Gary Darling, said that by pointing with his left hand, Thompson had signaled for a left-hander, and left-hander Oliver Perez was brought into the game. The Boston Red Sox rallied for six runs in the inning and won, 8-7.

"If there's anything there for me," Thompson told reporters afterward, "it's a lesson learned that if you make any motion with either hand, that's it. I didn't realize that."

The next morning, according to another baseball source, the play was the subject of much discussion in MLB offices in New York, and umpiring crew chiefs around the country were asked how they would have ruled. Opinion was divided almost down the middle, with half the crew chiefs saying they would have accepted Thompson's explanation and allowed him to bring in a right-hander.

On Monday, MLB issued this directive, which an industry source provided ESPNBoston.com, making it mandatory for umpires to base a pitching change on the first gesture by a manager.

The directive reads:

"Official Baseball Rule 3.06 governs substitutions including pitching changes and requires the manager to immediately notify the umpiring crew of any substitution.

"This Rule has been interpreted by the umpires to require the manager to stick with the pitcher he signaled for. Thus, if a manager notifies the umpiring crew that he is making a pitching change by clearly and unambiguously signaling for a left-handed pitcher with his left hand, or a right-handed pitcher with his right hand, that team is thereafter required to bring that pitcher into the game. If there is uncertainty when bringing a pitcher into the game (e.g., two left-handed pitchers warming up simultaneously in the bullpen and the manager signals only with his left hand), the umpire has the discretion to ask the manager to identify the substitute pitcher by name. If the wrong player attempts to enter the game under those circumstances, a correction can be made as long as it is done immediately.

"Please be advised that this rule interpretation will be interpreted strictly for the remainder of the 2013 season."