Hard by the left-field foul line, wedged between the bullpen and the football stadium, is a two-story building with offices for coaches and a classroom and clubhouse for players. This is where Tim Corbin, the coach of the Commodores, met an idol before a game in 2011.

Corbin, whose team is ranked No. 2 in the nation behind North Carolina, was born in Wolfeboro, N.H., in 1961, Carl Yastrzemski’s rookie season for the Boston Red Sox. Baseball captivated Corbin, and in his backyard, he copied Yastrzemski — hands held high, cocked shoulders, bat pointed to the sky. He admired so much about him, the way he played caroms off the wall, his crisp one-hop throws to second base, his disciplined approach to batting practice.

“Everything that guy did was about skill, about playing the game right,” Corbin said. “If you looked at Carl Yastrzemski, I don’t know if you’d say ‘five tools.’ Well, no, probably not. But everything he did was a winning play.”

Now Corbin coaches Yastrzemski’s grandson Mike, a senior right fielder who opened the weekend hitting .333 and has started every game since the middle of his freshman season. Carl Yastrzemski has seen two games in person, against Louisiana State in Mike’s sophomore season.

That weekend, Corbin told Yastrzemski that he did not think his grandson, who bats left-handed, had the power to put a ball over the Vanderbilt ballpark’s Green Monster, just outside the window.

Mike heard the conversation and walked off, silently. Then he faced Kevin Gausman — who would be the first pitcher taken in his draft class the next season — and lifted a fastball over the wall.

Mike autographed the ball and gave it to his grandfather, who told him, simply, “Nice swing.” But for all his highlights across 23 major league seasons — the Triple Crown, 2 World Series, 18 All-Star Games — this may have been Carl Yastrzemski’s proudest moment.

“I think it was more fun for me than for him, to see that happen,” he said over the phone last week. “You get more of a thrill out of your grandkids’ accomplishments than what I accomplished. I started working with Michael Andrew when he was 14 or 15. His father did a great job with him. I’m very proud of him.”

•

Michael Andrew Yastrzemski was born in Florida in 1990, the only child of his parents, Carl Michael Yastrzemski Jr., who also went by Mike, and his wife, Anne-Marie. Mike had been a switch-hitting outfield star at Florida State and reached Class AAA in a playing career that ended in 1988. He wound up one credit shy of a degree and never finished.

The couple divorced when young Mike was 6, and mother and son moved to Massachusetts, surrounded by grandparents, uncles, aunts and cousins. Three years later, Mike’s father moved up from Florida and found work as a manager in the produce department of a supermarket.

Carl Yastrzemski hit 452 home runs in the majors. Mike averaged eight a season in the minors. He told his son that he would rather hit a triple, anyway, because it gave him a chance to run with abandon. On their weekends together, he taught him to play hard, all the time.

“He was just always a guy who wanted to have fun — always laughing, pulling pranks on everyone, a jokester,” the younger Mike Yastrzemski said of his father. “He was a little bit of a wild man, hearing from my uncles. They’d go fishing in the Keys and he’d go diving in the water with sharks around, trying to swim under and catch fish, just enjoying where he’s at in the moment.”

One September day in eighth grade, when he was walking home from school, Mike saw his maternal grandfather, Charlie Wesson, pull up beside him in a car. Wesson had always been there for Mike, attending his games, winking when he faked a fever in grade school so they could spend the day together. This time, the news was bad. He needed to go home, immediately.

Young Mike saw a crowded house and knew something was wrong. His father had died of a heart attack after hip surgery. A short and difficult life was over, at 43, but the son thought largely about his mother. His parents were not married anymore, but he knew her life would change, too.

“I just felt like I had to pick myself up and my mom up,” he said. “It was a very tough time for her. I felt like I was trying to take control of my life and not rely on other people to do things for me.”

Yet there were other people, so many, he said, that he felt as if he had “10 brothers and sisters and all the aunts and uncles in the world.” He still played baseball and hockey and basketball. He was smart enough to be admitted to Brown and to have a good chance at Harvard, too.

And when his other grandfather, who lived nearby, would throw out the first pitch before the start of the World Series, in 2004 and 2007, Mike would get to go, even if Carl did not stay very long.

•

The name — that jumble of letters so famous that spell-check programs now recognize it — was not a burden to a young boy playing baseball in New England. It is all Mike Yastrzemski ever knew. But it always drew attention.

“I remember clearly, in Little League, being around people who didn’t really know who I was,” Anne-Marie Yastrzemski said. “They’d be saying silly stuff — ‘The only reason you’re on the team is your name; you’re not like your grandfather’ — and I wanted to turn around and punch them in the face. But you just have to keep your mouth shut and smile.”

When Mike was young, she said, coaches seemed afraid to offer much advice to a Yastrzemski. Her son wanted to be his own man — he turned down a chance to wear his grandfather’s No. 8 this season — and while he was proud of the name, he was naturally much closer to his mother.

“She’s a very strong person,” said Matt Hyde, a Yankees scout and a family friend. “They have not only a bond of mother and son, but they have a friendship you can see coming through.”

Charlie Wesson, who died during Mike’s freshman year in college, was an important father figure, she said. The mechanics of the role were different for Carl Yastrzemski because of his celebrity. In the minds of the fans, he belonged to them; no one ever played more games for one team. But Carl Yastrzemski, now 73, is a private man who does not seek or need attention.

When Mike — one of his nine grandchildren — was younger, Carl would get him tickets to Fenway with a pass to the players’ parking lot. For a birthday, he arranged for Mo Vaughn and John Valentin to meet Mike near the Red Sox clubhouse and sign some baseballs. The grandfather made it happen, but he was not there.

Mike did not seem to mind. He said he would rather have his grandfather to himself, to golf or fish for striped bass. Besides some photographs, he does not have a collection of Yastrzemski memorabilia. He has the real thing — and a personal hitting coach beyond compare.

After his father died, Mike and Carl grew closer. Dave Bettencourt, who runs a baseball academy in Haverhill, Mass., gave Mike a key to the facility so he could work in private with Carl on Sunday mornings during high school.

Carl’s brother, Richard, attends most Vanderbilt games and keeps him current, calling during and after every game. They recently helped Mike shake a slump.

“When he was struggling, he had his hands close to his body,” Carl Yastrzemski said. “He was putting too much weight on his back leg; he was all tied up. I talked to him on the phone after the game and, bam, he went on a tear.”

•

Mike Yastrzemski was at a camp for high school prospects at Florida State when Corbin, the Vanderbilt coach, called for the first time. The Seminoles, the program of his father, had thought he was too small and shown little interest. Yastrzemski said he knew Vanderbilt — where this writer graduated from in 1997 — only because of an N.C.A.A. video game. The virtual Commodores dominated the game because they were based on a team that included the future major leaguers David Price, Pedro Alvarez and Ryan Flaherty.

“So I was like, Oh, cool, I’ll check it out,” Yastrzemski said. “That was something that resonated with me at first, because it’s down in Nashville. When you’re in Massachusetts, you’re not hearing much about it.”

That has changed. Corbin’s roster now includes six players from Massachusetts, including the top starters Kevin Ziomek and Tyler Beede, a former first-round pick of the Toronto Blue Jays.

Beede, Yastrzemski’s roommate, said his father raised him on Yaz tales and still knows the words to a song about him. Mike Yastrzemski once lived in the Peabody section of campus and pronounces it “Peabidee,” the New England way. At Corbin’s direction, “Sweet Caroline” plays in the eighth inning of home games, as it does at Fenway Park. The concession stands might as well serve clam chowder.

“Guys like us go back home and talk about it — the city, being down here, the good group of kids we have,” Ziomek said. “The reputation builds off of that. Families talk, kids talk with each other. Playing summer ball, travel ball, the word kind of spreads.”

Anne-Marie Yastrzemski has done her part for the area’s high school players. She organizes an annual showcase game called the Rivalry Classic, at Fenway Park or Yankee Stadium, to give scouts an extra look at local talent. She said her former husband would have loved it.

Scouts have noticed their son. He was drafted out of high school in the 36th round by Boston, and again last summer by Seattle in the 30th round. The Mariners offered $300,000 — well more than the league-recommended bonus — and all remaining tuition costs.

Anne-Marie had long implored Mike to get his degree, and he had followed through with two selections to the Southeastern Conference’s all-academic team. He majored in crime and society and took advantage of his surroundings with a country music class as a freshman.

But he also felt a rapport with the Mariners and knew they had stretched their budget for the offer. He was undecided until the final minutes.

“The deadline was 5, and at 4:30, he called me and said he was going to sign,” Carl Yastrzemski said. “I said, ‘Well, it’s your decision.’ Then I waited, and at 5, he called me back and said, ‘No, I’m not signing, I’m going back to Vanderbilt,’ and the reason was that he promised his father he would get a degree before he signed to go to pro ball.”

The degree will come in a ceremony on Tuesday, and next month, almost certainly, a major league team will draft him, probably in the top 15 rounds. One National League scout, who asked not to be identified because his team had not authorized him to share opinions on players, said Yastrzemski had outstanding makeup but would probably have to overachieve to reach the majors. His power, the scout said, was limited.

Yastrzemski has just three home runs this season, but his grandfather said he did not discover his own power until he was 26. “He’ll learn to hit with power,” he said. “Right now, the main thing is to hit for average and drive in runs.”

His .333 average would be a career high, and Vanderbilt has a chance to win the university’s first national championship. Carl Yastrzemski will be paying attention, although probably away from the crowds.

•

Yastrzemski helps with Red Sox minor leaguers in spring training, but he does not like to fly. Life has not been easy lately; four years after losing his son, he had triple bypass surgery. The success of his grandson has helped. “It’s like a peace for him,” Mike Yastrzemski said. “I’ve got a bunch of other cousins who are doing really well, and just seeing all of us succeed and grow up, he’s really grown into that role over time. He’s gotten more comfortable with it. He realizes he’s not going to live forever.”

As he spoke, Mike Yastrzemski leaned against a dugout railing on the third-base line here, 200 feet or so from the wall that connects generations. After all that has happened, he said, his only surviving grandfather might have grown distant. Instead, they grew closer.

“I’m thankful for the way it turned out,” Mike Yastrzemski said. “Everybody stayed strong together.”