Ladislao Kubala, who led the line for FC Barcelona in the 1950s and 60s with great distinction, is being treated for a blood circulation problem in a clinic in the Catalan city.
Barcelona said in a statement on Monday that Hungarian-born Kubala, 74, was admitted to the clinic on 12 February because of a calcium deficiency in his blood. Further tests revealed a problem with blood circulation to his brain and he is due to be kept under observation until Wednesday at least.
Kubala, voted the greatest player in the club's history in 1999, Barcelona's centenary year, made his debut for the club in 1950 after arriving in Spain with a Hungarian team. He went on to help Barça to four Primera División titles, five Copa del Rey's and two Inter-Cities Fairs Cup triumphs before retiring in the 1961/62 season.
Kubala briefly coached Barcelona but was sacked in 1963. He then joined RCD Espanyol, where he made a comeback and played alongside Spain's other great import, the Argentinian-born Alfredo di Stéfano.
He also played 19 times for his adopted country, scoring eleven goals, in addition to coaching the Spanish national team for 68 games between 1969 and 1980. Kubala finished with a record of 31 wins, 21 draws and 16 defeats.