Both are a little more gray in the temples now, but as they reunited Wednesday afternoon to celebrate Giambi's return to the A's after a seven-year stint with the Yankees, it was more than a little obvious that the two men still share the same spirit.
Both blessed with the ability to artfully bounce between the roles of class clown and passionate professional, Beane, 46, and Giambi, who turns 38 on Thursday, alternately exuded giddiness, silliness and a deep commitment to the cause.
After splitting the first 14 years of his career with the A's, for whom he debuted in 1995, and the Yankees, with whom he signed as a free agent after the 2001 season, Giambi is back in Oakland on a one-year deal with an option for 2010.
And Beane, the general manager who saw Giambi leave town for $120 million eight years ago, re-introduced the slugger with such a profusely gushing opening statement that even he recognized that it bordered on over-the-top.
"At the risk of going on too long and telling everyone how much I love you, Jason ... I feel like I'm marrying my ex-wife," Beane said to uproarious laughter.
Giambi responded by playfully resting his head on Beane's left shoulder and wrapping an arm around Beane's right shoulder before snapping to attention and blurting, "I don't have a comment on that."
Surprisingly, Beane didn't have a comment on Giambi's getup before the newest and oldest member of the A's put on his familiar No. 16 home white jersey.
Beane normally delights in pointing out even the slightest idiosyncrasy in the appearance of those around him, but he left completely alone the fact that Giambi, whose casual ensemble was accessorized by a flinty, loose black scarf, looked like he'd just auditioned for a role in "The Pirates of Penzance."
Giambi chose not to don the A's hat that had been provided for the photo op with Beane and A's manager Bob Geren, explaining, "I spent too much time on my hair to put on this hat."
Also on the subject of time, Giambi said he thoroughly enjoyed his stay in New York, but he turned stone serious when talking about returning to his roots.
"I'm excited to be home," he said. "I started my career here and achieved a lot of great things, which got me the chance to play for a childhood dream with the Yankees. ... Now I'm coming full circle, like in life.
"But I didn't come here just to come back and be the prom queen again and ride through the floats [like], 'This is what I used to be.' I'm here to win. We're going to have a good time, but we're going to win games."
According to the Associated Press, Giambi will get a $4 million salary this season, with a $6.5 million club option for 2010 that features a $1.25 million buyout. Giambi also can earn an additional $500,000 each year in performance bonuses: $250,000 each for 525 and 550 plate appearances.
"I still see myself playing for a long time," said Giambi, who is four home runs shy of 400 for his career and has his sights set on 500. "I want to play at least three or four more years, but I understand that this is the way the market works. I'm excited to go out and play well and let that option kick in, and hopefully we can build something special here."
Beane, who earlier in the offseason added All-Star Matt Holliday in his effort to give more offensive support to his plethora of promising young pitchers, said the A's will get plenty of bang for their buck, both on the field and in the clubhouse.
"I'm looking forward to exercising the option," Beane said as Giambi nodded earnestly. "In our minds, he's still one of the best offensive players in the league. He was one of the best when he left, and for seven years he did the same things that he did for the Yankees that he did with us. We're looking forward to seeing more of that."
Giambi said he understands why many A's fans were "hurt" when he left for New York, but he hopes they're as excited about his return as he is.
"I always had a great rapport with the fans here," he offered. "Hopefully there's a little bit more of a buzz around the team now, and I hope the fans come out and support us."
Beane, meanwhile, could barely contain his excitement over bringing Giambi back into the fold.
"We're talking about a guy who has been one of the greatest Oakland Athletics ever on the field, but we're also talking about one of the most popular players we've ever had," Beane said. "Reconnecting with him over the past several hours, I never realized how much I missed him and all the positive energy that he puts out to the people around him. We got him as a baseball player, but we also realize that he's a great personality. He's an absolute gentleman and a great baseball player. He's a great teammate."
And, Beane added, a great example for Oakland's many young hitters.
"If I've said it once, I've said it a hundred times: Jason understands hitting more than any player I've ever been around," he said. "He totally got what we were trying to sort of sell here, and he was the best teacher we ever had. To be able to bring him back here at this point in our team's development is absolutely perfect.
"Listen, I like the 30 homers and 100 walks and 100 RBIs, but I also like the impact that he has on people. This guy understands offensive baseball better than anyone we've ever had here, and that's going to really resonate with some of these young players."
Giambi batted .247 with 32 homers, 96 RBIs and a .373 on-base percentage in his final season with the Yankees, to whom he likened to a traveling rock band. The A's of recent vintage have been more county-fair folk than anything, but Giambi figures to change that in a hurry.
He'll bring leadership, experience, personality and a big bat. And after seven years in the clean-shaven, corporate World According to Pinstripes, he'll bring back the biker look that epitomized the early-aught A's.
"I'm not as young as I used to be, so it might take some time to grow out my hair, but I'm going to stay scruffy, as usual," Giambi said. "A little more gray, but I'm still the same guy who likes to have fun. ... To put on the white shoes again, it's going to be pretty cool."
And the mustache? That caterpillar with a pituitary problem that graced his face last summer in the Bronx?
No mustache, Giambi said.
"That was just for a hitting streak," he said with a smile and sheepish shake of the head. "It was a bad look, but it got hits."
Mychael Urban is a national writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.