SAN FRANCISCO -- After his flight landed at San Francisco International Airport on Thursday, Giants president of baseball operations Farhan Zaidi lingered at his gate longer than usual. A part of Zaidi was still in denial, refusing to accept that he was about to watch the greatest catcher in Giants history walk away from the game.

Zaidi tried to delay the realization as long as possible, even as he sat on the dais at Oracle Park later in the afternoon as Buster Posey officially announced his retirement from Major League Baseball.

“I don’t know if this is the right time for it, but I just kind of wanted to ask, is this like a definite, for sure thing?” Zaidi jokingly asked.

It’s hard to imagine the Giants without Posey, a seven-time All-Star who developed into the foundational piece of San Francisco’s three World Series championships last decade. Posey’s decision caught many off guard, but in truth, the 34-year-old veteran entered this past season with an inkling that 2021 would be the final year of what was likely a Hall of Fame career.

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“I kind of went into this last season feeling like it might be my last,” Posey said. “I just gave myself some space in my mind to be OK with deciding otherwise if I wanted to keep playing. I just never really wavered. I think it really allowed me to really, really empty the tank this year like I never have before.”

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Posey responded with one of the best seasons of his 12-year career, batting .304 with an .889 OPS and 18 home runs while leading the Giants to a franchise-record 107 wins and their first National League West title since 2012. He had a $22 million club option for '22 that the Giants would have happily exercised, but in the end, Posey chose to go out at the top of his game, citing a desire to spend more time with his family with his health still intact.

“The reason I’m retiring is I want to be able to do more stuff from February to November with my family,” Posey said. “Physically, it’s much harder now, and to be honest, it’s hard to enjoy it as much when there’s physical pain that you’re dealing with on a daily basis.”

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Posey previously showed his commitment to his family by electing not to play in the pandemic-shortened '20 campaign after he and his wife, Kristen, adopted twin baby girls, Ada and Livvi, who were born prematurely in July 2020. The couple also has a second set of twins, Lee and Addison, who recently turned 10.

Posey’s voice caught as he recognized his family in his opening remarks, thanking Kristen for “the love and support from the first game to the last,” and adding that being a father to his four kids is “the greatest joy in my life.”

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Posey was motivated to come back and play in 2021 to show that he could rediscover his prime, and he accomplished that goal en route to winning Sporting News’ National League Comeback Player of the Year Award for the second time in his career.

Despite his resurgent season, Posey felt the physical toll of playing the most demanding position in baseball was catching up to him and eroding some of the joy of his on-field success. Posey sustained a horrific left ankle injury following a home-plate collision with Scott Cousins in 2011, underwent season-ending surgery on his right hip in '18 and has also missed time with concussions throughout his career.

Posey recognized that he could have probably pushed through the pain and kept playing for a few more seasons, but he felt it was the right time to hang up his spikes.

“I can honestly say, no, playing the way I did didn’t sway me,” Posey said. “I think that’s part of the reason that I do feel at peace with my decision, because obviously it would be much harder if I felt otherwise.”

Posey, of course, has nothing left to prove. He won the 2010 NL Rookie of the Year Award, '12 NL MVP honors, four NL Silver Slugger Awards (he’s a finalist for another one this year), one NL Gold Glove and the '12 NL batting title.

“The reality of a future without you and your family and how much you meant to us at least on the field has been something for us to all digest,” Zaidi told Posey. “Even with that mixed feeling is a sense of overwhelming gratitude for everything you’ve meant to this organization.”

Posey said he plans to move back to his native Georgia to be closer to his extended family in the near future, though he still plans to remain involved with the Giants in some capacity. He knows it’ll be strange not to report to Scottsdale, Ariz., once Spring Training rolls around in February, but he expects to still have his hands full.

“It will definitely be different,” Posey said. “But you can see the babies crawling on the windowsill over here. I’m pretty sure we’ll stay busy.”