"It's not illegal to take prescription drugs but it is illegal to take them if they're not prescribed to you and we've made it very clear as to the ramifications...
"[We are also] making sure we're prescribing the right quantity. It's really important that we make sure there isn't the opportunity for that sort of thing to happen."
Doyle and the coaching staff have had extended meetings with the five players and their representatives over the past week, and the door is open for the quintet.
"We've now spent some time with them and they are all focusing on the future," said Doyle. "So I would imagine they'll be available for selection."
Coach Andrew McFadden faces a dilemma. It would be foolhardy to keep last week's inexperienced lineup for the Panthers, as they will struggle to maintain the same energy, but he will want to reward some of the young players who performed against the Dragons. Doyle also indicated that Tui Lolohea, Thomas Leuluai and Simon Mannering will be available.
Halfback Shaun Johnson admitted it had been a difficult time at the Warriors.
"I was chomping at the bit to get into Kiwis camp," said Johnson after the Anzac test. "It's good to be around different players but I'm looking forward to getting home and continuing what we are trying to do. It's been a tough time for us but hopefully we can put it that bit behind us and attack the rest of the season."