The renowned English blues guitarist Green launched Fleetwood Mac in 1967, naming the band after himself and its rhythm section, drummer Mick Fleetwood and bassist John McVie.
Nicks joined Fleetwood Mac in 1975, long after Green departed (in 1970), but the impact of his formative era in the band was not lost on her.
"When I listened to all the Fleetwood Mac records, I was very taken with his guitar playing," she wrote via Twitter. "It was one of the reasons I was excited to join the band. His legacy will live on forever in the history books of Rock n Roll. It was in the beginning, Peter Green's Fleetwood Mac, and I thank you, Peter Green, for that. You changed our lives."
After splitting with guitarist Lindsey Buckingham in 2018, Nicks explained that the band was eager to perform more music from Green's era during its ensuing tour.
Later in her statement, she named her "biggest regret" as not being able to "share the stage" with Green.
"I always hoped in my heart of hearts that that would happen," she wrote.
Green, who is best known for writing "Black Magic Woman," was one of the few tragic figures in rock and roll to actually survive battles his with drug addiction and mental illness.
But the challenges of the '60s and '70s took its toll, as Green almost completely withdrew from music and public live after leaving Fleetwood Mac. He took menial jobs and refused to accept royalties into the early-'90s.
Despite his attempts to put his past behind him, he was revered by the likes of B.B. King and Eric Clapton. His uniquely-voiced 1959 Gibson Les Paul "Greeny" — which now belongs to Metallica's Kirk Hammett — is reportedly worth millions.
"No one has ever stepped into the ranks of Fleetwood Mac without a reverence for Peter Green and his talent, and to the fact that music should shine bright and always be delivered with uncompromising passions!!," he added in a statement.
Peter Frampton called Green "one of the most tasteful guitar players ever." Black Sabbath bassist Geezer Butler added that Green was "one of the greats."
David Coverdale recalled playing a gig in a local band supporting Fleetwood Mac in the '60s. He wrote that Green was a "breathtaking singer, guitarist and composer" and an artist he "truly loved and admired."
Kiss's Paul Stanley added that Green was one of the four greatest guitarist to ever come out of England. While Living Colour's Vernon Reid noted that Green is a "perennial guitar topic...a guitarist's guitarist" and an "unsung giant of the art of blues rock."
Having owned Green's iconic Les Paul since 2014, Hammett finally got to meet the legend this past winter. He documented the reunion between Green and "Greeny" and even recorded with the Fleetwood Mac founder at Abbey Road studios.
The project was slated to be released this year.