Posey suffered the injury while blocking home plate in the 12th inning of San Francisco's game against Florida Wednesday night. Last year's NL Rookie of the Year was placed on the disabled list. An MRI confirmed Posey had a fractured left fibula and three torn ligaments in his left ankle, Giants trainer Dave Groeschner said.
Posey's agent, Jeff Berry, said Thursday morning he reached out to Joe Torre, leader of on-field operations for Major League Baseball, and raised the idea of changing the rules regarding plays at the plate. He also spoke with the players' union about the play.
According to sources, the Major League Baseball Players Association has been in contact with Berry, about the concern Berry has expressed about contact plays. The MLBPA will consider internally the discussion, and if the players' leadership decides to pursue more action, it will then reach out to Major League Baseball to discuss changes.
Over time, it is has become accepted practice for catchers to block home plate, and for baserunners to launch themselves into catchers.
"You leave players way too vulnerable," Berry said. "I can tell you Major League Baseball is less than it was before [Posey's injury]. It's stupid. I don't know if this ends up leading to a rule change, but it should. The guy [at the plate] is too exposed.
"If you go helmet to helmet in the NFL, it's a $100,000 fine, but in baseball, you have a situation in which runners are [slamming into] fielders. It's brutal. It's borderline shocking. It just stinks for baseball. I'm going to call Major League Baseball and put this on the radar. Because it's just wrong."
When asked about that type of play, Torre told ESPN Radio's Colin Cowherd simply such scenarios are a long-standing part of baseball that should not be changed.
Scott Cousins scored the go-ahead run in a brutal collision with Posey at home in the 12th inning, injuring the star catcher in a 7-6 loss to the Marlins.
"I don't know how frequent they are to warrant any rule change, and certainly sometimes when there is something that happens it is unfortunate, but I don't know if there's enough there to rewrite the rulebook," said Angels manager Mike Scioscia, a former major league catcher.
Berry, in a statement issued Thursday after he'd contacted MLB and the players' union, said Posey was in front of home plate and never blocked the plate, while Cousins, who had room to slide, lowered his shoulder as he approached home.
"At [the] point of impact, all of Buster's body is still two feet in front of the plate leaving all of the plate exposed for the runner," Berry said.
The play came after the Giants rallied from four runs down in the ninth in one of the wildest nights of their young season.
The deciding play came when Emilio Bonifacio hit a shallow fly ball to right-center off Guillermo Mota (2-1) for the second out. Cousins tagged from third base on the sacrifice fly, beating the throw from Nate Schierholtz and lowering his shoulder to slam into Posey for a clean -- albeit cringing -- hit on the reigning NL Rookie of the Year.
Cousins was safe as Posey never quite could corral the ball. Cousins, who attended the University of San Francisco, lives in the Bay Area and had almost a dozen friends and family in attendance, said he felt sorry for injuring Posey but believed it was a clean baseball play.
"I felt like he was blocking the dish. It's the go-ahead run to win the game, I got to do whatever I can to score," Cousins said. "I'm not trying to end anybody's season or anything like that. I just was trying to play hard and score the go-ahead run. He didn't say much and you could tell he was in pain.
"And when their manager, when Bruce (Bochy) came out, he was pretty frustrated. I didn't want to make things any more tense."
After several minutes of being attended to at the plate, with fans finally chanting "Posey! Posey!" he was helped off the field by two team trainers, holding his left leg and looking stunned.
"It's the toughest play in baseball. You hate to see it," Bochy said. "As a catcher you know what it's like, and you don't like it. Believe me. When I see him laying there, it's certainly not a good feeling."
Cousins said he felt for Posey and repeatedly mentioned that he wasn't trying to injure him. He said he would find a way to contact Posey to wish him well.
"It's a baseball play. I feel bad for Buster Posey, I really do," Cousins said. "I'm going to send a message over there to them."
Buster Olney covers Major League Baseball for ESPN The Magazine. Information from The Associated Press was used in this report.