Hall of Fame pitcher Phil Niekro has passed away at the age of 81.

Phil Niekro rode his signature “butterfly” knuckleball to 318 wins over 24 seasons. He spent 20 years with the Milwaukee/Atlanta Braves and briefly played for the New York Yankees, Cleveland Indians, and Toronto Blue Jays.

He was first called up to the bigs in 1964 and finally hung up the cleats in 1987, at 48 years old.

Phil Niekro used the knuckler more effectively than any player in baseball history, and it enabled him to record an MLB-record 121 wins after turning 40.

“I never knew how to throw a fastball, never learned how to throw a curveball, a slider, split-finger, whatever they're throwing nowadays,” Phil Niekro once said. “I was a one-pitch pitcher.”

https://www.youtube.com/watch?v=eZKWxn1zR9o

Overall, Phil Niekro was 318-274 with a 3.35 ERA in his career. He ranks fourth on the all-time innings pitched list, trailing only Cy Young, “Pud” Galvin, and Walter Johnson.

He was inducted into the Baseball Hall of Fame in 1997.

Phil Niekro died in his sleep after a prolonged bout with cancer. The Atlanta Braves announced his passing on Sunday.

“We are heartbroken on the passing of our treasured friend, Phil Niekro,” the Braves organization wrote in a statement. “Knucksie was woven into the Braves fabric, first in Milwaukee and then in Atlanta. Phil baffled batters on the field and later was always the first to join in our community activities. It was during those community and fan activities where he would communicate with fans as if they were long lost friends.

He was a constant presence over the years, in our clubhouse, our alumni activities and throughout Braves Country and we will forever be grateful for having him be such an important part of our organization.”

MLB Commissioner Rob Manfred also released a statement about Phil Niekro.

“Phil Niekro was one of the most distinctive and memorable pitchers of his generation. In the last century, no pitcher threw more than Phil's 5,404 innings. His knuckleball led him to five All-Star selections, three 20-win seasons for the Atlanta Braves, the 300-win club, and ultimately, to Cooperstown.

“But even more than his signature pitch and trademark durability, Phil will be remembered as one of our game's most genial people. He always represented his sport extraordinarily well, and he will be deeply missed.”

Phil Niekro was born in Blaine, Ohio, on April 1, 1939. His brother, Joe, was an All-Star pitcher, as well.

Phil Niekro joins the unfortunately long list of accomplished ballplayers to pass away in 2020, including Hall of Famers Bob Gibson, Al Kaline, Joe Morgan, Lou Brock, Tom Seaver, and Whitey Ford, and icons such as Dick Allen and Don Larsen, among others.