“I may be nostalgic, but I don’t like to live in the past,” Yogi Berra tells Reggie Jackson early in Eric Simonson’s "Bronx Bombers," an ultimately maudlin sports drama now having its world premiere at The Duke on 42nd Street. It’s the summer of ’77, and Berra, a Yankees coach, is trying to get his right-fielder to move on from a famous dugout brawl with manager Billy Martin.

With his unforgettable style, Berra (Richard Topol, earnest) is urging Jackson (Francois Battiste) to recognize he can’t have it both ways: the team can’t succeed as a whole if the star player stays angry. But trying to have it both ways is what Simonson (“Magic/Bird,” “Lombardi”) seems to be doing in “Bronx Bombers,” which begins as a promising examination of power and personality clashes, and in its second act becomes a too-sentimental, surreal fantasy -- all fields of dreams. 

With a dedicated ensemble that keeps the play moving apace, “Bronx Bombers” is set during two fated periods in team history. Act one unfolds during that year early in the Steinbrenner era, when the Yanks would go on to win their 21st World Series. Much of the second act takes place in 2008, on the eve of the transition from old stadium to new.

We begin as Berra, assisted by captain Thurman Munson (Bill Dawes), is attempting to negotiate peace before Martin (Keith Nobbs, frothing like a rabid cat) gets himself fired, or Jackson vents to the tabs. Baseball insiders and armchair fans alike will appreciate the careful dialogue, like when Martin says, “I’d probably be in jail if it wasn’t for baseball,” or when Berra makes a casual aside to Munson, whom he suspects of considering a move to Cleveland: “Then maybe you could give up that plane.”

The meatiest parts of the scene are reserved for Battiste, as the power-hitter who still feels diminished by his teammates. “Bronx Bombers” repeatedly comes around to the subject of money, first, here, as Munson reveals his disdain that Jackson’s contract is better than his own. In the second act, Derek Jeter (Christopher Jackson) appears, to tell a fellow player almost apologetically: “Money’s a sideshow.”

From the hotel room, we move to the Berra homefront, where Yogi and wife Carmen (Wendy Makkena, Broadway’s “Side Man”) are coping with 30 pounds of potatoes they’ve found dumped on their lawn, the result of some less-than-politic remarks Berra made on a trip to North Dakota. Steinbrenner has floated the idea of Berra taking over for Martin, and the coach and his wife are debating the merits.

We’re still in the Berra household as the second act begins, but matters go far afield as dinner guests start to appear. Knock-knock, it’s Elston Howard (Battiste, again), the first African-American on the Yankees’ roster. In short order, we’re seated around a table with Lou Gehrig (John Wernke), Joe DiMaggio (Chris Henry Coffey), Mickey Mantle (Dawes), Babe Ruth (C.J. Wilson) and Jeter.

As the hard-living Babe, Wilson energizes the dinner party, serving as foil to Jackson’s compact, by-the-playbook Jeter. A nice moment that has the shortstop walking Babe through all the decades of history between them moves into cringe-worthy territory when Jeter raises the spectre of 9/11. It’s couched in terms of things the Yankees “have come back” from, but it feels self-indulgent here.

The back half of the second act, equally saccharine, has Berra passing a baton of sorts to Jeter in the locker room, the day of the last game at the old stadium. A young sports reporter is on hand, reminiscing about Munson’s death and Jackson’s heyday, and then Jackson himself arrives for a photo-op: “I wish they didn’t have to tear this place down,” Jackson says.

Of the roundly talented performers, Topol (stepping in late for Joe Pantoliano, who departed due to “creative differences”) stands out, for his endearing way with Berra’s era-bridging legacy, even as he’s forced to repeat one too many of those Yogi-isms. As both Jackson and Howard, Battiste seems to be having the most fun, strutting around like a peacock despite not quite being sized like a ballplayer. Makkena, as Carmen Berra, is a worthy partner to her husband.

Bill White, the longtime sportscaster, is heard calling games before the play begins. Another nice touch: a turn-off-your-phones announcement from WCBS radio color commentator Suzyn Waldman. Scenic designer Beowulf Borritt spruces up the Duke’s black box, superimposing a façade over the second-level seats to make them look like the mezzanine of the old Yankee Stadium.

Simonson’s play starts out full of promise, but in the end gives up footing, much like the 2013 version of the team it’s trying to understand.

"Bronx Bombers," through Oct. 19 at Primary Stages at The Duke on 42nd Street. Tickets: $70. Call 646-223-3010 or visit dukeon42.org.

Follow Robert Kahn on Twitter@RobertKahn