Almost every baseball story is sad, John Grisham says.

The reason? Because “it’s about unfulfilled potential and broken dreams and all that,” the popular author recently said on NPR. “There are a lot of good baseball stories, but almost all will break your heart, just like the game.”

Case in point: Joseph M. Schuster’s novel “The Might Have Been.”

It’s a lovely, poignant, heartbreaker of a baseball novel, as good as last year’s hyped “The Art of Fielding” and more literary than Grisham’s “Calico Joe.”

With the St. Louis Cardinals World Series champs off to a good start, the whole season full of promise, April seems like a cruel time to bring up any sadness embedded in baseball stories.

Schuster, head of the communications department at Webster University, loves the Cardinals and uses them as the golden ring for his fictional baseball hero.

Like other fans, he notes with wonder the miracle of last fall’s World Series Game 6, when David Freese’s home run in extra innings proved that real baseball sometimes surpasses any fictional heroics.

“I happen to think there’s a lot about baseball that’s stunning,” Schuster says.

But the author knew he didn’t want to write the “conventional baseball narrative” about scrappy underdogs who come through on the last pitch.

“Writers have to be cruel to their characters,” he says.

Schuster doesn’t expect his own novel to be a megaseller, Grisham style. But he seems happy with its good reviews and plugs from some of the country’s best literary writers (Charles Baxter, Margot Livesey, Richard Russo). Livesey says: “At the heart of Joseph M. Schuster’s remarkably eloquent novel is Edward Everett Yates, a character so fully human that he demands our complete attention. Many readers will surely find their own lost dreams in this brilliant debut.”

In typical Midwestern understatement, Schuster, 59, says in a recent interview: “I think it is a solid piece of work. … I hope this doesn’t sound narcissistic.”

The brilliant debut took the father of five about a decade to write. Schuster worked so long on the story his youngest not only went through puberty, the kid graduated from high school and college.

Although baseball stories may trade in sadness, “The Might Have Been” isn’t corny or mawkish. Like most adult baseball novels, it also focuses on relationships. And like most baseball games, there are touches of grace and hope — even when things seem bleak.

It’s giving away little to divulge that Schuster’s protagonist is a minor league player for the Cardinals who, when he finally makes the team at age 27, has his dream deflated almost immediately.

It’s 1976, and Edward Everett Yates’ first at bat comes after Lou Brock gets hurt while sliding. The rookie fantasizes about making a dramatic hit but is ordered to put down a sacrifice bunt.

Schuster writes of Yates: “Still, he thought, he was here. There was a uniform in a locker across the street with his name on it and only six hundred men out of how many tens of millions of men in America could say that. Tomorrow was another game and the day after another still. He would have his chance and he would do something with it.”

Soon, Yates is getting on base at a game in Montreal. But it’s right before the Expos have a new, roofed stadium, and the Redbirds are playing on a lousy field in the rain. Next stop for Yates — a hospital bed.

He learns he can make more money selling flour, but baseball calls him, and Yates spends decades sacrificing much for the game.

Schuster says his novel isn’t just about baseball players who had only a brief career in the big leagues: “A lot of people really believe they are going to be, say, the next American Idol or a winner of ‘America’s Got Talent.’ A lot of people have dreams they can’t let go.”

Schuster interviewed players whose careers lasted less than a season and he acknowledges some, such as Robert Slaybaugh, whose “tragic injury in a spring training game kept him from ever appearing in the major leagues.”

He talks about Glenn Gardner, a rookie at 29 who pitched for the Cards in 1945. He had only one big league season and ended up managing an unaffiliated Class C team in Lockport, N.Y.

Gardner died of cirrhosis, and his widow wrote a “sad and touching” letter to baseball officials asking whether there might be any benefits for her, Schuster says.

“That manifested for me that it’s hard to let go” of baseball, the author says.

One reason the novel took so long to write is that not only does Schuster teach, he writes short stories and freelance journalism (he’s done work for the Post-Dispatch, the Riverfront Times, Cardinals Gameday Magazine and others).

Schuster grew up in a small town in Ohio. A graduate of Northwestern University, he has his master’s of fine arts from Warren Wilson College. Russo was his thesis adviser, and Livesey has been a teacher and editor. Schuster says he wrote about 1,000 pages for “The Might Have Been,” which have been cut down to just 330.

The ninth draft of the book was submitted to Livesey’s literary agent, who sold the novel to Random House’s Ballantine imprint.

Schuster says he’s working on a new novel about a college professor whose life is “falling apart.” It’s not autobiographical, says the novelist, who seems to have plenty of reason for dreaming as he nears 60.

Lucky for him, writers are far less prone to career-ending injuries. And they can hit the majors at almost any age.