England batting great Geoffrey Boycott was on Sunday readmitted to hospital after suffering a setback in his recovery from throat surgery, his family revealing "things have taken a turn for the worse".
The 83-year-old was discharged from hospital only on Friday after a successful operation to remove a cancerous tumour.
However, he has now developed pneumonia.
"Thank you all for the well wishes, we've been blown away by the sheer number of them," read a statement from the family on Boycott's X account.
"Unfortunately, things have taken a turn for the worse and my father has developed pneumonia and is unable to eat or drink so is back in hospital on oxygen and a feeding tube for the foreseeable."
Boycott had previously been treated for throat cancer in 2002 with chemotherapy and radiotherapy.
Boycott is one of a select group of cricketers to have scored 100 first-class hundreds.
For England, he scored more than 8,000 runs in 108 Tests at an average of nearly 48.
He also captained England in four Tests in 1978 in place of the injured Mike Brearley.
After his 24-year first-class career ended with Yorkshire sacking him in 1986, Boycott established himself as both a newspaper columnist and a noted broadcaster, developing a global fanbase.
He was a particularly popular figure in the Indian sub-continent.
In 2020, his 14-year stint as a commentator on BBC Radio's Test Match Special came to an end.
Boycott said at the time that the quadruple heart bypass surgery he underwent in 2018, together with the coronavirus pandemic, were factors in his decision to end his BBC career.