South Sydney pair Dylan Walker and Aaron Gray remain in intensive care after overdosing on prescription drugs on Tuesday.
Both players were prescribed painkillers following post-season surgery last week, but were found vomiting by a mutual friend at Gray's Sydney apartment in the early hours of the morning.
The Rabbitohs duo were then rushed to St Vincents hospital in a critical state, but South Sydney chief executive John Lee said they had both improved and were now in a stable condition.
"They were fairly heavily sedated for some time but I can report to you now that both players are showing signs of (being awake) and we think that will improve more in the coming hours later today," he said.
Police have begun an investigations, while South Sydney have also informed the NRL's integrity unit.
"The number one priority is the welfare of these two young men," NRL boss Dave Smith said.
"Any questions that need to be asked will be asked."
Early toxicology reports indicate there was no use of illicit drugs, and Lee believes the players were not drinking alcohol.
He did not know the exact type of medication or how much either player took but early reports suggested Walker had been prescribed painkillers Oxycodone and Tramadol.
Lee also moved to distance the club's medical staff confirming the drugs were prescribed by specialist doctors.
"Dylan Walker, who's been a lifelong friend of Aaron's, came round to his place, where they watched some movies," Lee said.
"This is medication that's not taken for fun. This is medication that is taken for pain, and it is becoming clear that they took too much of that medication."
"We'll need to know what the toxicity information is as it becomes available."
The NSW Ambulance service confirmed both players were found in a critical condition at Gray's apartment.
Walker, 20, played four games for Australia after playing a starring role in the club's breakthrough premiership win last year and had surgery on his left hand.
Gray, 21, made his first grade debut this season and scored seven tries in 12 matches, earning himself a two-year extension at Redfern.
Gray had surgery on his right knee.