Lincolnshire Police said Mr Grey died in hospital after being attacked at his home in Westwick Gardens last October.
Two men have denied killing a pensioner in Lincoln who died after being subjected to a "disturbing" level of violence.
Rocky Curtis, 24, and Robert Holmes, 23, both from Wisbech in Cambridgeshire, are charged with the murder of 70-year-old Sonny Grey.
Lincolnshire Police said Mr Grey died in hospital in Nottingham after being attacked at his home in Westwick Gardens last October.
Speaking shortly after his death, Detective Chief Inspector David Wood said: "He was subjected to a disturbing level of violence and his injuries were extensive."
Holmes, of Redmoor Lane, and Curtis, of Newbridge Lane, both pleaded not guilty to the murder of Mr Grey at Lincoln Crown Court this morning, a court spokeswoman said.
They were both remanded in custody to appear at the same court on October 12 for a further plea and case management hearing. A trial is expected to take place early next year, the spokeswoman added.