Former Portugal great Eusebio was back in the hospital for the third time in two months.
Lisbon's Hospital da Luz said the one-time Benfica star spent the night in care due to high blood pressure.
Doctors said they decided to keep Eusebio in the hospital overnight after he attended a routine examination on Monday. They say he is expected to be discharged within 48 hours.
Eusebio spent Christmas in the hospital with double pneumonia. He was readmitted several days later with severe neck pain.
Eusebio da Silva Ferreira, who turned 70 last month, became a Portuguese superstar after standout performances in the 1960s and was named one of FIFA's 10 best football players of all time in 1998.