Former Brazil striker Ronaldo is reportedly in intensive care in an Ibiza hospital after coming down with pneumonia.
Ronaldo, 41, was rushed to a local hospital on Friday evening before being diagnosed with the illness, according to local news publication Diario de Ibiza.
The same report claims that the Brazilian asked to be transferred to a private hospital on the same day, although this has not yet been confirmed.
Ronaldo, who came down with tropical disease dengue fever in 2012, owns a house in Ibiza, and is a regular visitor to the island.
The former centre-forward is widely regarded as one of the best players to have ever played the game, having enjoyed successful spells with the likes of Barcelona, Inter Milan and Real Madrid.
Two-time World Cup winner Ronaldo retired from professional football in 2011 following a two-year spell with Corinthians.