Johan Cruyff has been diagnosed with lung cancer, his former club Ajax have confirmed.
Spanish media reported the news on Thursday, and Ajax director Edwin van der Sar said on the club website: " We have had contact with his manager, Carole Thate, and she confirmed to us that Johan indeed has lung cancer.
"It has just been discovered, so they could not yet provide much more information. On behalf of the club, I wish Johan and his family a lot of strength and a speedy recovery."
Cruyff, 68, is regarded as one of football's greatest ever players having won the Ballon d'Or three times, in 1971, 1973 and 1974, and led Holland to the final of the World Cup in 1974.
He is most strongly associated with Ajax and Barcelona, playing for and managing both teams.
He oversaw a golden period at the Nou Camp, which included winning the European Cup in 1992, and has been cited as a major influence by many of those he used to manage, most notably Bayern Munich and former Barca boss Pep Guardiola.
Cruyff was a heavy smoker prior to double heart bypass surgery in 1991, after which he took to sucking lollipops on the touchline.