Davis remained under surveillance at Sydney’s Royal Prince Alfred Hospital on Tuesday after he was found distressed and in serious pain in the Giants’ rooms on Saturday night.

Minutes earlier, the 23-year-old had taken part in the club’s jubilant on-field celebrations in the Spotless Stadium arena, unaware of the dire ramifications of a blow to his kidney during the opening quarter.

Giants officials on Tuesday night were not prepared to disclose the full nature of Davis’ injury after a series of procedures over Monday and Tuesday although they said Davis was conscious and in the company of family and club officials. The club said it was too early for a final diagnosis but remained confident Davis would make a full recovery.

It is understood Davis, the former Crow who was the first out-of-contract player to declare late in the 2011 season that he was moving to the Giants, was hopeful he had not suffered any long-term organ damage and that major surgery could be avoided.

He remained unaware that the first-quarter hit – an accidental bump to the kidney in a clash with Sydney’s Craig Bird – had had any serious impact until after the final siren. Davis lined up on Sydney’s star recruit Lance Franklin and, ultimately, won the battle against the big forward in the Giants’ upset win.

The loss of his right kidney was expected to end the elite football career of Geelong’s Tom Lonergan after the Cats’ defender suffered severe lacerations and bruising when he backed into a marking contest against Melbourne’s Brad Miller in just his seventh AFL game.

Lonergan returned to the VFL the following year and, after being redrafted by Geelong in 2008, played a key role in the club’s 2011 premiership in the grand final against Collingwood.