Jamaal Lascelles and Karl Darlow are NOT yet ready for the Premier League, according to Steve Stone.
The pair joined Newcastle United last year from Nottingham Forest.
But they were loaned back to the Championship club, and only reported for training on Tyneside this summer.
Ex-Forest player Stone – who was first-team coach at Newcastle under Alan Pardew and John Carver – feels they are on a steep top-flight learning curve.
Asked about 22-year-old defender Lascelles, Gateshead-born Stone said: "He'll definitely take time.
"What he is at the minute is someone who needs to learn the game at Premier League level.
"It's totally different to the Championship, let me tell you. He needs to fit into structures, not just his own game.
"This is a great learning curve for him this season. There's no pressure on him.
"He's played a couple of games. He's not quite ready yet, but maybe next season he'll be better for it.
"He's got the presence and the attributes. It's about transferring that to the highest level.
"He needs to understand what Premier League centre forwards do. They're a totally different level to what he's used to."
Stone believes Darlow, 25, is unfortunate not to be training with Tim Krul, with the club's No1 goalkeeper having suffered a season-ending injury.
He told the Nottingham Post: "He needs to be around top coaches and keepers.
"He needs to watch what Tim Krul does every day.
"It's a real shame Tim is out for the season. He's lost the chance to watch and learn what the best do.
"Tim is a World Cup keeper for Holland and a Premier League keeper for five years. Karl can learn from him.
"He's young. You look at keepers who are 27 or 28 and they're still learning. He's in the right place. Newcastle give youngsters a chance. They buy cheap. With no disrespect to Forest they've come from a lower club. They'll try to get him to the next level."