In the family tree of Major League Baseball, there are plenty of fathers and sons who have played the game at its highest level. There are just three families, however, that have played it through three generations -- the Bells, the Boones and now the Hairstons.

"And one day," outfielder Scott Hairston of the New York Mets said, "we might have a fourth one."

Landon Hairston, 5, and his brother, Dallas, 3, are a bit removed from the prospect stage, but both boys know their father is a Major League player. And they also know about their uncle Jerry, an outfielder with the Washington Nationals, and their cousin Jackson, who is also 5 years old.

Before too very long, the kids will learn their baseball lineage from their fathers. They'll hear all about how it began with their great grandfather, Sam Hairston. Scott remembers learning about the game that way.

"We had many conversations before he died," Scott said. "Times were tough when he played in the '40s and '50s."

Sam Hairston was a catcher, restricted by baseball to play in the Negro Leagues with teams like the Birmingham Black Barons and Indianapolis Clowns. They traveled by bus, stayed in rundown rooming houses and ate where they could at a time when players of color were not embraced by baseball.

In 1951, four years after Jackie Robinson broke baseball's color barrier, Sam Hairston broke the color barrier for the Chicago White Sox. He appeared in just a handful of games, his only taste of big league ball as a player. But it was the beginning of a 40-year career as a scout and coach in the White Sox organization, and it was in that role that he signed his son, Jerry Hairston Sr., as a fourth-round selection in the 1970 MLB First-Year Player Draft.

"My grandfather always expressed a love for the game," Scott said. "All who knew him said he was a great man. He always said you have to treat the game with respect."

Sam Hairston passed that approach on to his sons. Jerry reached the Majors in 1973 with the White Sox and after a year with Pittsburgh, he was sold to Durango of the Mexican League. After four seasons on the fringes of professional ball, well-removed from the Majors, he returned to the White Sox in 1981 as a valuable utility player. He led the American League in pinch hits for three straight seasons and taught some important lessons to his own sons, future Major Leaguers Scott and Jerry Jr.

"My father is very much like my grandfather," Scott said. "He always said, `Remember who you are. Be yourself. Don't be somebody else.' I keep that in mind every day."

The brothers Hairston grew up, understandably competitive, wondering what it would be like to play together. "We have a third brother, Justin, who played college ball," Scott said. "I was the peacemaker."

Jerry Jr., four years older than Scott, reached the Majors with Baltimore in 1999. There were stops with the Chicago Cubs, Texas, Cincinnati and the New York Yankees before he signed with San Diego in 2010. At last, there was a reunion with Scott, who had logged time with Arizona and Oakland as well as the Padres.

"It was very cool to be together for that season," Scott said. "It was something we always thought about as kids."

After one year together with the Padres, the brothers Hairston went their separate ways again, Jerry signing with the Nationals and Scott with the Mets. Both occupy similar roles as valuable bats off the bench, continuing the Major League legacy for the third generation of ball-playing Hairstons.

And for the future, perhaps a fourth.

"Maybe one day," Scott said, smiling broadly. "We'll see."

Hal Bock is a freelance writer based in New York.