It has been along for the ride with Keith Hernandez through a co-MVP season in 1979, World Series titles in 1982 and '86, a guest appearance on "Seinfeld" in 1992 and since 2006 as an SNY analyst.
It starred in a famously hokey advertising campaign and was honored by both Newsday and the American Mustache Institute for its long and meritorious service.
Soon, though, it will be no more.
"I can always grow it back," he said. "It doesn't take very long if I don't like it."
Hernandez, 58, began pondering the imponderable as his 'stache turned from dark to gray this season following the discontinuation of a series of commercials in which he appeared for "Just For Men," a hair coloring product.
"It just looked noticeable that I'm gray and this is my true color and that's probably one of the reasons why -- just to shave it off and see how it looks," he said.
"I am completely gray now. I look like Charley Weaver on 'Hollywood Squares.' "
Earlier this month, Hernandez mentioned off-handedly during a game that he was thinking of shaving.
Naturally, when it comes to Keith Hernandez and his mustache that qualified as news, so soon he found himself being approached by Schick Hydro offering to sponsor the event, with proceeds going to a cause close to his heart.
The center offers care for elderly people unable to be on their own, allowing family caregivers the freedom to work. Keith helped raise $1.75 million in his first five years of involvement. His mother, Jacqueline, suffered from Alzheimer's Disease when she died in 1989.
"I wasn't going to do it," he said. "I didn't want anybody thinking I'm trying to draw attention to myself and be narcissistic."
But the charitable component made it a "win-win," he said.
Hernandez believes there were three previous times in his adult life that he shaved, including 1977, when Cardinals manager Vern Rapp forbade facial hair, and briefly as a Met in 1987.
In 2007, he won both Newsday's "Mustache Madness" contest and an American Mustache Institute poll that named his the best sports mustache ever.
Now this. Schick has hired Elliott Chester, a Las Vegas-based barber with a celebrity clientele, to do the honors at about 11:45 a.m. in the plaza outside Citi Field. (There is no current plan for what will become of the hair itself.) SNY will show highlights during the game against the Pirates.
"We know the Schick Hydro Power Select will change everything Keith thinks he knows about shaving," associate brand manager Steven Charles said, "and we think he will find the shave so comfortable and refreshing that he'll ditch the 'stache for good."
The news caused an emotional reaction on Twitter Thursday.
@maura: "Hold me."
@emmaspan: "If anyone needs me I'll be under my desk in the fetal position, sobbing."
What would Hernandez tell fans who are upset? "Get over it," he said. "C'mon, it's ridiculous. It's not like I'm having the roots pulled off my upper lip. It can make a guest appearance down the road."