The 70-year-old has returned to the hospital in Lisbon as he continues to battle ongoing health problems
This is the third time that the 70-year-old has been admitted to the medical facility in Lisbon in little over two months.
Eusebio spent almost two weeks at the hospital before Christmas due to bilateral pneumonia, before being re-admitted in early January because of acute cervical pain.
The former Portugal international felt unwell on Sunday and was rushed to hospital by ambulance on Monday morning, according to news daily A BOLA.
Meanwhile, the Hospital da Luz medical staff have stated that Eusebio will be discharged 'in one or two days' as they wish to monitor his recovery.