Baseball's most important joint is the mending left ankle of a young catcher in San Francisco, a hinge upon which the Giants' playoffs hopes this year might, well, hinge.
Buster Posey suffered a fracture in his lower left fibula and severely strained ligaments in his ankle when the Marlins' Scott Cousins collided with him while he attempted to block the plate in the 12th inning of a tied game last May 25. The injury set off a firestorm across the baseball world as players, managers, coaches, executives, writers and TV talking heads discussed endlessly the merits of blocking the plate and new measures to protect catchers.
When that maelstrom faded, however, left behind was a Giants lineup lacking a leader and a run producer and a player facing a long process of rehabilitation. Posey had surgery four days after the incident, wore a cast and then a walking boot but it was more than three months before he could resume baseball activities.
And now, on the eve of his flight to Arizona to report to the Giants' spring training facility in Scottsdale, comes the best news for denizens of San Francisco: Posey said that his ankle feels "good" and that he's been "on schedule" throughout the whole recovery process.
"I'm excited to ramp it up and just feel like a baseball player again," he said by telephone from his native Georgia.
Posey, who will turn 25 a week before the season starts, won 2010 NL Rookie of the Year honors after batting .305 with a .357 on-base percentage, .505 slugging and 18 home runs in 406 at bats while catching and often batting fourth for the eventual World Series champs.
In what was supposed to be his first full season in 2011, Posey had a .284/.368/.389 batting line with four homers through 162 at bats; he was reaching base more often than he had as a rookie, even if his power was down somewhat.
Then, the injury. And the man used to plying his trade with bats and chest protectors was now spending his time doing rehab and physical therapy.
But under the supervision of Giants head trainer Dave Groeschner, Posey is looking like a strong bet to bounce back and be a major contributor. And to keep Posey's bat on the field as much as possible in 2012 and to lessen the rigors of catching, the Giants plan to use him at first base with some regularity, potentially once a week or so, a proposition Posey has been open-minded about.
"[My ankle] feels good and has progressively gotten better and better," Posey said. "The biggest concern, I think, coming back from this was to gain my range of motion back, and I feel like I completely have my range back almost 100 percent. If it's not 100 percent, it's really close. I'm happy with it. I think the next hurdle will be seeing how it withstands games, what kind of endurance it's going to have. I'm confident that it'll respond well."
How valuable was Posey in 2011? San Francisco was 25-18 (.581) in his 43 starts and 61-58 (.513) in the 119 games someone else caught. For perspective's sake, the Diamondbacks won the NL West last year with a .580 winning percentage -- one point less than the Giants' record with Posey.
San Francisco's pitching staff was so good that the Giants won 86 games despite scoring an NL-low 570 runs -- one of only two teams with a winning record while scoring fewer than 600 runs in the past two decades -- and the replacement catchers provided little offense.
Backups Eli Whiteside, Chris Stewart and Hector Sanchez combined to hit .205 in 378 at bats, with just a .276 on-base percentage; if those rate stats had been for an entire season, the average would have ranked last in the NL and the OBP would have been second-to-worst.
Posey was in the clubhouse most days for rehab, but the severity of his injury helped mitigate any frustration he might have felt about not being on the field.
"I feel like I've always done a good job of not worrying about stuff that's out of my control," Posey said. "There was no way I was going to be able to play at that point. I was in a cast for a while and then I was walking around in a boot. I think it would have been more stressful to watch if I was right on the cusp of being healthy -- just the physical state I was in, I knew there was really no way I was going to be able to contribute."
Posey stayed in San Francisco to rehab for most of the summer, taking his first fully weight-bearing steps in early August. While around the team, he made himself available if pitchers had occasional questions but generally tried to stay in the background.
"The way I felt is that, if someone wants to ask me something, I was going to be there and do what I could do in the state that I was in," he said. "But at the same time I knew that one of the best ways that I could eventually help out was to be as diligent as I could with my rehab and come back healthy this coming season."
He relocated to Arizona in mid-September, took batting practice on the field in October and caught the bullpen sessions of a few of the Giants' minor league pitchers in November before returning to Georgia for the winter.
Back home, Posey did a lot of tee work in the cage but also had a mighty fine personal pitcher for batting practice: his youngest brother, Jess, is a high school senior headed to the University of Georgia next year to join the baseball team as a preferred walk-on.
"He can throw it up there all right, probably upper 80s," Posey said, admiringly, of his brother. "But he hasn't been pumping it in there like that [against me]."
By reporting to camp a week before Giants pitchers and catchers were expected to report, Posey allotted himself more time to ease back into the schedule. And one of his first plans is to stand in on the bullpens a few pitchers are throwing so he can see the velocity again and hone his eyes on changeups, curveballs and everything in between.
He hopes to participate in the club's Cactus League opener on March 3.
"For me personally, that's a goal," he said. "I'm going to listen to our training staff. They know what they're doing and I'm not going to do anything silly, but I would love to catch an inning or two in the first game, get an at bat or two or whatever it might be. That's definitely the next goal. It's going to be nice just to be back in some action."
Talk of being ready for Opening Day -- San Francisco starts its season on April 6 in Arizona -- certainly seems realistic if his Cactus League debut goes as planned, but it's too early to make definitive proclamations. What can be said for now is that Posey has adhered to his rehab program and put himself in good shape to be ready for spring training, so he can see how the ankle responds to the unpredictability of game situations as opposed to the controlled environment of workouts.
"There's really no way to know," he said. "You've got to get out there and do it."
When -- and how well -- he does it might very well determine the Giants' season.