One of their friends noticed that Gray was vomiting and dialled triple-zero to avoid a potential tragedy.
Both players had undergone post-season surgery - Walker on his left hand and Gray on his right knee - and the details of the incident that landed them in hospital remain clouded.
However it has again brought the abuse of prescription medication by NRL players to the fore.
Lee said both players could undergo counselling and clinical care to treat their issues.
St George-Illawarra and former Kiwis test halfback Benji Marshall said while the abuse of prescription medication was less common since the NRL clamped down on it several years ago, it was still prevalent.
"It's a wake up call," Marshall said.
"Throughout my years in club teams and in rep teams, I've seen players take prescription drugs recreationally.
"It's fine to take them to ease pain or if you've had an operation, but to take them recreationally instead of drinking, it's when you cross the line."
Warriors doctor John Mayhew last year described the NRL's prescription drug abuse problem as "widespread" but told Fairfax media earlier this year that his observations indicated it wasn't as common this season.
"As a result of problems [in the NRL] we've had a mandate to be very careful of our prescription of drugs like Tramadol [and] the hypnotics" Mayhew told the Sydney Morning Herald back in May.
"We've been aware of that and, certainly, on this side of the Tasman, we don't have a problem.
"Talking to the Kiwi players who played in the [Anzac Test] from the Warriors, there was no issue there. Unless I'm being naive the message seems to be getting across and doesn't seem to be the issue this year as the last few years."
Walker, 20, played four games for Australia in last year's Four Nations after playing a starring role in the Rabbitohs breakthrough 2014 premiership win.
Gray, 21, made his NRL debut this season and scored seven tries in 12 matches, earning himself a two-year extension at Redfern.
- With AAP