The former Manchester City youngster could appear in the first-team picture sooner than anticipated.
The 17-year old was snapped up on a free transfer by the Magpies after spending time in Manchester City’s academy and initially joined up with the under-18 squad.
But his potential has quickly been noted and he has already made two appearances for Peter Beardsley’s Under-21 team, report the Chronicle.
The Ghana-born defender is comfortable at left-back or in central defence and his accelerated development would be welcome given Newcastle’s injury crisis on the left flank.
Massadio Haidara and Paul Dummett are both out injured but their absence has thrust relatively unknown Swiss youngster Kevin Mbabu to the fore. Adu-Peprah isn’t considered ready for the first team yet but has a two-year contract in which to impress on Tyneside.
Successful academy graduates have been rare at Newcastle in recent years and a return to an ethos of promoting from within would be a welcome change of tact.
Next up for the Magpies is a Premier League clash against previous table toppers Manchester City. It's set to be yet another tough test for Steve McClaren's side - although Newcastle did beat City in the Capital One Cup last campaign.