"No doubt, you don't want to lose him any longer than you have to," Giants general manager Bobby Evans said hours before his club played the D-backs at AT&T Park on Tuesday. "You want to get him back as fast as possible."
Posey was inadvertently struck in the helmet by a 94 mph Taijuan Walker fastball during the first inning of Monday's 4-1 win over the D-backs.
As Posey sat stunned in the batter's box attended by manager Bruce Bochy and athletic trainer Dave Groeschner, a sellout crowd went completely silent. To say that it put the kibosh on home opening festivities at AT&T Park was an understatement.
Posey showed no concussion symptoms before he left the ballpark Monday, Bochy told the media. But when he was examined Tuesday morning, there were signs of some problems.
"There's been some lingering stuff, I'm not going to get into details," Posey said. "Overall I feel good. We just thought it was the smart move especially being a catcher, having the one yesterday. You can get hit in the mask by foul tips and you never know whether potentially you're going to have some more. So I'll take a week and be ready to go."
If Posey is OK, he'll be eligible to return when San Francisco opens a two-game set in Kansas City against the Royals next Tuesday night.
But it's still frightening in the moment whenever it happens.
One of the scariest in memory was Goose Gossage hitting Ron Cey in the head during Game 5 of the 1981 World Series between the Yankees and Dodgers at Dodger Stadium. And another was Roger Clemens beaning Mike Piazza on July 8, 2000, during the back end of a rare Yankees-Mets day-night doubleheader that began at Shea Stadium and ended across town at the old Yankee Stadium.
Cey and Piazza suffered concussions. In all three cases -- Cey, Piazza, Posey -- the sound of ball striking helmet was so resounding it sent a chill up everyone's collective spine.
When Posey got up Monday on his own and walked to the dugout, the relief was palpable. Before doing so, he took inventory of his body movement and cognition.
"I was just seeing how I felt before I popped up, and for the most part, I felt pretty good," he said. "I wasn't really dizzy and I didn't feel out of it or anything. But when you're dealing with your head, you have to use caution. It's not like a hip or knee or anything, so I feel like it's the right move."
On the current Giants, Brandon Belt and Joe Panik have missed significant time with concussions. Mike Matheny, a former catcher and now manager of the Cardinals, had his career end here in 2006 because of head injuries. Matheny later said he suffered hundreds of concussions because of foul tips off his face mask.
A concussion victim is more susceptible to the next one and its dreaded companion, post-concussion syndrome. Matheny lived in a fog for more than a year.
Posey said he doesn't think he's suffered previous concussions.
"I'd like to say I haven't had one," he said. "Knock on wood, I feel like I've been fortunate in that regard."
The Giants have worked around long-term losses to significant position players like Belt, Panik, Hunter Pence and Angel Pagan, still making the playoffs and winning the World Series. But Posey is the heart of the team.
That became only too clear in 2011 when Posey had his left leg broken and ligaments torn in that ankle because of a collision at home plate with Scott Cousins of the Marlins. The incident led to significant rules changes regarding how a runner must approach a catcher as he speeds towards the plate.
Posey was hurt on May 25 with the Giants in first place in the NL West by 2 1/2 games. They finished the season 86-76, eight games in arrears of the division-winning D-backs.
No player is irreplaceable, but Buster is close. He's the defacto captain behind the plate and owns a .333/.373/.476 slash line with 117 homers and a .850 OPS in a little less than nine seasons.
Posey has won the NL Rookie of the Year Award, the NL Comeback Player of the Year Award, the NL MVP Award and the Hank Aaron Award. He, Madison Bumgarner and Matt Cain are the only three players remaining who were members of all the World Series-winning teams.
"Hopefully I won't be out for a long time. I don't anticipate it being a long time," Posey said. "We'll take it day by day. I have full trust in the medical staff and the training staff. And I think all will be well."
Certainly, that's the hope.