He suffered a knee problem and won’t be involved in next week’s Europa League game against Maritimo at St James’s Park.
Alan Pardew: “Adam’s injured – he hurt his knee a couple of weeks ago.
“It isn’t serious – he just needs rest.”
Campbell became the youngest player to have represented the club in Europe when he came off the bench in Newcastle’s Europa League qualifier against Atromitos in Athens in late August.
Reserve-team coach Willie Donachie: "He will only return to action when the club’s medical staff are convinced he’s ready.
“I think it’s going to be a while yet – the physios are being cautious about it, and rightly so.
“He’s going to be a special player if he progresses like we hope.”
Source: Newcastle United Mad