As a jittery and insecure rookie, Willie Mays went 0 for 12 before finally breaking through with a home run off the great Warren Spahn.

“I’ll never forgive myself,” Spahn later joked. “We might have gotten rid of Willie forever if I’d only struck him out.”

Nice try. Mays is still going strong as the Giants gear up for his 80th birthday celebration Friday night at AT&T Park. That’s right, eightieth. That symbol of boyish enthusiasm, that ebullient icon of baseball’s most glorious summers, is now the Say Hey Octogenarian.

Mays, born May 6, 1931, remains a one-man whirlwind, making speaking engagements, running his charitable Say Hey Foundation, visiting the ballpark and offering baseball tips to any Giants players brave enough to ask. Spry and lively, he is the spokesman for HealthSpring as well as for The Institute on Aging in San Francisco.

Glaucoma, which has hindered his eyesight, is his only major health issue.

“I’ll always take care of him. I wish him a happy 80 more,” said Giants equipment manager Mike Murphy, a bat boy when Mays and the Giants moved west in ’58. “I think of him as a father, and he thinks of me as a son.”

Major League Baseball officially bestowed the title of Greatest Living Ballplayer upon Joe DiMaggio in 1969, and he wore that crown for the last 30 years of his life. No such “greatest living ballplayer” label exists for Mays. For one thing, the tag is superfluous — being introduced as Willie Mays about covers it. For another: Why limit the field to the living?

“I can’t believe Babe Ruth was a better player than Willie Mays,” Dodgers pitcher Sandy Koufax once said. “I can’t believe he could run as well as Mays, and I can’t believe he was any better an outfielder.”

In the greatest living ballplayer debate, you might get an argument from the Hank Aaron fan base or from those who give the edge to Mays’ godson, Barry Bonds.

But you would get a more strenuous debate by asking what Mays did best on the diamond. He remains the epitome of the five-tool player, someone who could hit for power (660 home runs), hit for average (. 302), run (338 stolen bases), field (12 Gold Gloves) and throw (witness him rocketing the ball back to the infield after “The Catch” in the ’54 World Series).

“Every part of his game stood out,” Joe Morgan, another all-around player, says in a Mays documentary to air Sunday on Comcast SportsNet Bay Area. “When he was in the outfield, he made plays that changed the game; when he was on the bases, he ran the bases and changed the game; when he was at bat, he definitely changed the game.”

From that vast array of skills, Mays’ throwing arm is the most often overlooked. But not by former Giants owner Peter Magowan, whose first glimpse of Mays was watching fielding drills from the stands at the Polo Grounds in May of 1951.

Magowan and his buddy got to the game early and noticed Alvin Dark covering third base while taking incoming throws from the rookie center fielder. It was love at first flight.

“Mays threw 15 balls to third base, each on one bounce, each to the exact same spot,” Magowan recalled. “Alvin Dark never so much as moved his glove. Throw after throw after throw “… “

In discussing Mays’ five tools, Hall of Fame broadcaster Lon Simmons added a sixth: intelligence. “If he had chosen to go to college and picked another path in life, he would have been successful in any field,” Simmons said. “He could figure things out.”

On the field, that meant Mays was always one step ahead. Simmons recalled Mays twice going from first to home on a hit-and-run single, both times by duping a fielder who suffered only a split-second lapse.

“Willie Mays was not the fastest guy in baseball, but he was the quickest to react,” Simmons said. “Go to a game now and watch how long it takes a runner to react on a wild pitch — there are times when it’s practically to the backstop.

“Willie was gone before that ball passed home plate.”

Simmons recalled another instance in which Mays’ brain made a quick read, during a visit to a gravely ill 9-year-old boy whose dream was to meet his hero. When Mays and Simmons walked in the house, Mays detected instantly that the kid’s perfectly healthy brother, only a year or two older, was feeling neglected and overshadowed.

“Willie walked into the house and figured out the situation immediately,” Simmons recalled. “He said, ‘Come here. I need your help. These are my car keys. I need you to go out to the trunk and bring in a dozen baseballs. This is very important. Do you think you can help me?’

“And the kid just lit up. And when Willie walked into the sick kid’s room, that child just lit up, too.”

Mays isn’t always as diplomatic around adults. He can be gruff. But his soft touch with kids is part of the reason the Giants savor his work as a team ambassador (official title: assistant to the president).

Making Mays an active part of the organization was one of Magowan’s first acts after assuming ownership of the team in 1993. Mays has a lifetime deal, which is why Magowan was surprised a few years ago when Mays approached him about a contract extension.

“Willie, it’s a lifetime contract. You know what that means, right?” Magowan said.

“I know what it means. I still want an extension,” Mays replied.

And so it was that Mays negotiated a deal that stretches into the afterlife. He will be paid one year after he’s gone, as an added extra layer of security for his wife, Mae, who has Alzheimer’s.

Suffice to say, the Giants are getting his money’s worth. At the ballpark on Friday, Mays will be honored during a pregame ceremony. The first 20,000 fans will get a mini-replica of the statue that sits outside 24 Willie Mays Plaza.

The real thing, meanwhile, keeps going and going.

“The line I always used to describe him is, ‘Willie Mays was the happiest guy in the world about being Willie Mays,’ ” Simmons said. “That’s what he wanted to be: He wanted to be Willie Mays.”

Mercury News staff writer Andrew Baggarly contributed to this report. Contact Daniel Brown at his Hot Read blog at blogs.mercurynews.com/49ers.