"No more home plate collisions?! What is this? NFL quarterbacks are catchers now?" Oakland outfielder Josh Reddick wrote.
"Nothing better than getting run over and showing the umpire the ball. Please don't ban home plate collisions," Pittsburgh rookie catcher Tony Sanchez posted.
Discussion to limit or ban collisions has intensified since May 2011, when Posey was injured as the Marlins' Scott Cousins crashed into him at the plate. Posey, San Francisco's All-Star catcher, sustained a broken bone in his lower left leg and three torn ligaments in his ankle, an injury that ended his season.
Posey returned to win the NL batting title and MVP award in 2012, when he led the Giants to their second World Series title in three seasons.
In Game 5 of this year's AL championship series, Detroit backstop Alex Avila was pulled a couple of innings after being run over at the plate by Boston's David Ross, a fellow catcher.
"This is, I think, in response to a few issues that have arisen," Alderson said. "One is just the general occurrence of injuries from these incidents at home plate that affect players, both runners and catchers. And also kind of the general concern about concussions that exists not only in baseball but throughout professional sports and amateur sports today."
Former catchers Joe Girardi, Bruce Bochy and Mike Matheny — all now managing in the majors — attended Wednesday's meeting.
"I don't think it's completely sparked by anything that's happened in baseball as much as what's happening outside of baseball and how it's impacting people and impacting the welfare of each sport," said Matheny, now managing the St. Louis Cardinals.
MLB intends to have varied tiers of punishment.
"I think there will be two levels of enforcement," Alderson said. "One will be with respect to whether the runner is declared safe or out based on conduct. So, for example, intentionally running over the catcher might result in an out call. So I think that the enforcement will be on the field as well as subsequent consequences in the form of fines and suspensions and the like."