Quini spent the majority of his career with Sporting Gijon, who he represented prolifically either side of his 1980 to 1984 stint with Barca.
He won the Pichichi trophy for being the top scorer in La Liga five times and remains eighth on the all-time list in Spain's top flight thanks to 219 goals across 448 appearances.
Quini represented Spain at the 1978 and 1982 World Cups, along with the 1980 European Championship.
His honours at Barca included Copa del Rey triumphs in 1980-81 and 1982-83 – scoring twice against his beloved Sporting in the former final – and the 1981-82 Cup Winners' Cup.
Te echaremos de menos, Brujo. DEP. Mi pésame a la familia y amigos pic.twitter.com/UuTNEH47T6— Andrés Iniesta (@andresiniesta8) February 27, 2018
Barcelona might have completed a Liga and Copa double in 1980-81 but their title bid faltered in astonishing circumstances when Quini was kidnapped at gunpoint after scoring twice in a 6-0 win over Hercules
He was released 25 days later, choosing not to press charges against his captors, and finished the season as La Liga's top scorer.
David Villa is another striker who learned his trade at Sporting before moving to Barca and Spain's all-time top scorer led the tributes to his mentor.
Cuando daba mis primeros pasos en esta profesión tuve la suerte de ser bendecido por los consejos del mejor delantero español de todos los tiempos, nunca podría haber llegado donde llegué sin tu ayuda al comenzar mi carrera. Te estaré eternamente agradecido amigo. Recuerdo que me pediste que algún día fuera mejor delantero que tú y te pido perdón por no haberlo conseguido pero es que eso era una misión imposible para cualquier delantero que quisiera intentarlo. Te vamos a echar mucho de menos no solo porque has sido el mejor como delantero sino porque también lo has sido como persona. Estoy seguro que ahí arriba te han reclamado porque en el equipo del cielo necesitan goles y se han llevado al mejor. Siempre vas a estar en mi recuerdo. Te quiero mucho brujo. DEP
"When I took my first steps in this profession I was lucky to be blessed by the advice of the best Spanish striker of all time, I could never have arrived where I arrived without your help," he wrote in an Instagram post.
"I will be eternally grateful, friend. I remember that you asked me one day [to be] a better striker than you and I apologise for not succeeding, but that was an impossible mission for any striker who wanted to try.
"We will miss you very much, not only because you have been the best as a forward but also because [of how] you have been as a person.
"I am sure that they have claimed you up there because in the sky they need goals and they have taken the best. You will always be in my memory. I love you so much, wizard. RIP."
Barca captain Andres Iniesta tweeted: "We'll miss you brujo. RIP. My condolences to family and friends."
The La Liga giants' president Josep Maria Bartomeu said: "Dismayed by the death of Quini, an extraordinary player and an incredible person who won a privileged place in the hearts of the Barca players and the world of football. Our heartfelt condolences to your family and friends."
Sporting adorned their club crest on their official Twitter page with a black ribbon and posted a short message.
"With great regret we can reveal the passing of our dear Quini. RIP," it read.