According to the newspaper, Blatter’s life is not in danger, but his condition is serious.
"My father is in a hospital. He is getting better every day. But he needs time and rest," Joseph’s daughter, Corinne Blatter Andenmatten, said, as quoted by Blick.
In December, the former FIFA head said that he had tested positive for COVID-19 but later recovered from the virus.
Blatter was removed from office in 2015 in light of the corruption scandal at FIFA and has been suspended from football for six years.
The former FIFA president is also subject to another criminal investigation in Switzerland over allegedly illicit payments.