Greater Western Sydney co-captain Phil Davis is expected to be in intensive care for another 24 hours after he was discovered to have bleeding from his kidney.
Davis received an accidental knee to the side late in the first quarter of the Giants' historic win over the Sydney Swans.
He finished the game before getting rushed to hospital, where he's been in intensive care ever since in the company of his family.
It's expected he will remain in hospital recovering for another week.
"Phil received a significant injury to his kidney after accidental contact in the first quarter of Saturday’s game," Giants chief executive officer David Matthews said in a statement on Wednesday.
"He played out the game, but was taken to hospital after the match when he started to feel pain.
"He was diagnosed with bleeding from his kidney and treating this has been the focus of doctors over the past three days.
"We are pleased that he has shown some very positive signs over the past 24 hours which is encouraging for everyone.
"His family has been with him during this time and wish to thank everybody for their thoughts and well wishes.
"Our primary concern is obviously Phil’s health and recovery.
"At this stage it’s still hard to say how long that recovery period will be but he is progressing well and resting comfortably."
Fellow Giants defender Heath Shaw credits Davis' "amazing" ability to play on after a serious kidney injury as an "important part" in the Giants' historic win over the Sydney Swans, especially given he kept one of the "top three forwards" in the AFL to one goal.
Davis had his ribs taped up during the game and it wasn't until after the final siren that it was thought to be more serious.
Shaw said he was too focused on his own role during the game to notice whether Davis was playing under duress.
The former Collingwood defender said Davis' efforts were all the more remarkable given who he was marking – $10 million man Lance Franklin.
Davis kept Franklin to just 1.1 in his first game for the Swans since the former Hawthorn forward turned his back on the Giants to join their cross-town rivals in the off-season.
"It's obviously fairly serious if he's still in hospital and to play out the game like he did, it was pretty amazing," Shaw said.
"At the time I didn't think anything of it, I thought he just copped a knock to the ribs and got it strapped up.
"Looking back at it now, seeing what he went through and he was playing on probably the best, if not top three, best forwards in the land and he set himself for that task on Buddy.
"He knew if he was to nullify him it would go a long way to us being competitive and hopefully winning the game.
"And when you look back at it you realise how much of an important part he played."
Shaw remembered a similar incident in Collingwood's 2010 premiership when defender Ben Reid played out the decider with a broken foot.
It happened in the replayed grand final, after the Pies had drawn with St Kilda the first time around.
"He had a broken foot and was hobbling around and I was telling him to pull his head in and just do what he had to do," Shaw said.
"We didn't find out until after the game he had a crack in his foot and he was in a moon boot for four weeks."
Key defender Tim Mohr (foot) is still three weeks away from returning, but Shaw said Stephen Gilham, Aidan Corr and Lachie Plowman were possible replacements for Davis if he was unavailable for the next game – against St Kilda on Saturday week.
The Giants will also be without midfielder Rhys Palmer (hamstring), who will miss three to four weeks.