The pair were the only two of 544 players, checked under the Football Association's compulsory doping control programme last season, to test positive.
FA officials have declined to identify the teenager, who has just completed a rehabilitation programme at an unnamed clinic, and have appealed for his anonymity to be preserved to assist in his recovery.
Alan Hodson, head of sports medicine for the FA, said: "He's gone through a substantial rehabilitation programme and the FA and his club aren't prepared to name him to protect his anonymity in order to assist him in his rehabilitation.
"It's been a long process and it's a long fightback for him, and naming him would just make things more difficult. He's got an uphill battle, a battle which is tough enough when people don't know what position you have been in. We would appeal to people to respect his predicament and the fact that he's got a problem that he has to fight against that is not easy to beat at the best of times.
"The FA, the PFA and his club have done everything to try to help him and there are clinical reasons for his privacy to be respected as he continues his rehabilitation programme. It's a long, hard road which he has already made some progress along, but now he needs all the help he can to continue that."
Newcastle would not comment on the matter last night but are understood to have played their part in the youngster's treatment. Although the 17- year-old has not been identified, it is believed that he had been nowhere near first-team recognition.
Details of the failed tests were revealed earlier this month, although the identity of the teenager's club was kept secret. He admitted his problems after being interviewed over the failed test and was already in treatment when the matter was made public.
It is the first recorded case of a British player confessing addiction to a Class A drug. Over the last five years, the FA has carried out more than 2,000 random tests, with only 29 proving positive. Next season, the programme will be stepped up to almost double last year's tally.
Michael Owen, who has been out of action since April because of a persistent hamstring injury, has been added to the Liverpool party for the match against Valerenga tomorrow.
Owen will also continue his intensive treatment, and some light training, under the watchful eye of the club doctor, Mark Waller, who will also make the trip.
The Liverpool manager, Gerard Houllier, has moved swiftly to confirm defender Dominic Matteo's future at the club following claims that Celtic wanted to buy him for around pounds 5m.
Houllier said: "First of all, Dominic is not for sale. I have had no contact with Celtic, but if they were to add another zero to the figure being put forward, maybe we would talk.
"I'm always proud and honoured that people seem to want our players but Matteo is not for sale and the player does not want to leave."Reuse content