Jewish sports fans and history buffs are paying special attention to this week’s Major League Baseball American and National League division series: If the Houston Astros and Los Angeles Dodgers, who were leading their respective series at the time of publication, make it to the World Series, it will be one of few times the Fall Classic will feature identified Jewish players on the rosters of both teams.

Outfielder Joc Pederson plays for the Dodgers; third baseman Alex Bregman for the Astros.

Bob Wechsler, a retired journalist who lives near Durham, N.C., and is author of the newly published “The Jewish Baseball Card Book” (Jewish Major Leaguers, Inc.), which includes the card of every known Jewish player who has played at least one game in the major leagues, said the last time that the Series posed Jew vs. Jew was in 2004, when Gabe Kapler played for the Boston Red Sox and Jason Marquis for the St. Louis Cardinals.

Before that: 1959, when pitchers Sandy Koufax and Larry Sherry played for the Dodgers, and Barry Latman for the Chicago White Sox. Legendary Detroit Tigers slugger Hank Greenberg figured twice in Jewish athletic history: 1945 (Cy Block played for the Chicago Cubs) and 1940 (Morrie Arnovich played for the Cincinnati Reds.)

Those are the only such matchups that Wechsler, who grew up in York, Pa., and as a child came here to attend Brooklyn Dodgers games in Ebbetts Field, has been able to find.

The first-known Jew to play in the World Series was Erskine Mayer of the 1915 Philadelphia Phillies, Wechsler said.

It’s not surprising that two teams with Jewish athletes may play in the Series, Wechsler added. The number of Jewish players in the majors has steadily increased in recent years. “There’s more teams, there’s more people” on teams’ rosters, he said. “Jews have assimilated into American life.” And so there’s no longer an onus for an athletically inclined young man to seek his fortune in sports instead of the traditional Jewish doctor-lawyer-accountant professions.

The criteria for inclusion in Wechsler’s baseball card book are simple: at least one Jewish parent, and “you have to be willing to be identified as a Jew … and not follow another religion.”

Pederson, 25, from Palo Alto, Calif., is Jewish on his father’s side and was eligible to compete for the Israeli team in the 2013 World Baseball classic. Bregman, 23, from Albuquerque, N.M., is a member of the city’s Congregation Albert, a Reform synagogue.

The possible confluence of two Jews in the Series “will be an interesting side note” for Jewish sports fans, Wechsler said.

His book includes player stats up to 2016. There’s a chance he might revise it, with this year’s World Series results, if the initial printing of 3,000 books sells out.

An Astros-Dodgers matchup will present an uncomfortable situation for one Jewish educator in L.A. next week.

Rabbi Ari Segal, who serves as head of school at the Shalhevet High School in L.A. after working in the same position in Houston’s Beren Academy, faces telling his rabid Dodger-fan friends that he favors the Astros — especially after the hit that Houston suffered in Hurricane Harvey this summer.

“At the risk of ruining my career here in Los Angeles,” Rabbi Segal said, tongue in cheek, in a telephone interview this week, “I have to say I’m pulling for the Astros. It’s a scrappy team.”