“The Phenom” is a sensitive, unconventional baseball tale rendered in the muted tones of dread, a young player’s fear of letting everyone down.

It’s about a rookie pitcher (Johnny Simmons) trying and failing to cope with the pressures of a fat contract, a brutishly demanding mentor/father, the girl he left behind and his own very public failure — a flurry of wild pitches in a key game — on national TV.

That’s a lot to ask of an 18-19 year old. So Hopper Gibson’s been sent to see a “mental coach,” a sports psychologist played with understated whispers by Paul Giamatti.

Hopper’s sessions on the couch are laced with flashbacks — distracted in class in high school, teenage flirtations, that magic moment when the scouts discovered him and the day he showed his mother “the castle” he bought her with his signing bonus.

Then, there’s Dad. Growing up in tiny Port St. Lucie, Florida, everybody knows Hopper and worse, knows his family. Hopper Sr., given a tattoos and a ferocious prison mullet cut with a performance to match by Ethan Hawke, knows the game. He once had promise, too.

He ridicules the kid, amused that baseball scouts are interested “in a little toothpick like you.” He insults his intelligence.

“I think you don’t have any homework. You don’t have the BRAINS to have homework.”

But in between prison stints and eruptions of rage, the old man’s given the boy every overbearing lesson the game taught him.

“Never show emotion on the mound.”

Simmons, of “Scott Pilgrim vs. The World” and “The Perks of Being a Wallflower,” makes Hopper both a convincing pitcher (no small feat) and shy, soft-spoken and thoughtful, even when he’s passing on Dad’s nasty “everybody uses everybody” lessons to his leftist, smart and underwhelmed by his impending fame girlfriend (Sophie Kennedy Clark).

There’s a lightly comical scene where he has dinner with her and her left-of-liberal parents, who surprise him with their suggestions that common sense dictates he pursue the riches the game might dangle in front of him over the enriching and maturing and broadening experience of college.

Writer-director Noah Buschel (“Neal Cassady” was his debut) conjures up a serene and unhurried character study, a 90 minute film so unhurried that it feels much longer. Simmons’ Hopper seemingly on simmer throughout. We see the trials of his public failure, the press scrum circling him like chum in the water. We hear about another pitcher who cracked up and killed himself and fear for the kid’s future.

A clever musical cue sets the mood. Buschel uses Mozart’s wistful and sad Piano Sonata #11 throughout the picture — in the score, a piece being practiced by a horn player in the high school band, and a ballpark organist’s between-innings scene-setter. It tamps down the tempo and puts us in Hopper’s frame of mind.

He’s in his glory, but it’s all coming apart. It’s all this kid can do to tamp down his emotions, get a handle on his fears and calm himself. Maybe a little Mozart would help. And sessions with a shrink.

MPAA Rating: unrated, implied violence, alcohol use, sexual situations

Cast: Johnny Simmons, Ethan Hawke, Sophie Kennedy Clark, Paul Giamatti
Credits: Written and directed by Noah Buschel. An RLJ Entertainment release.

Running time: 1:30