Jose Mourinho sent the left-back out on loan during his spell as manager at Inter Milan, predicting great things for the youngster "once he gets his head together".
But former Toon defender Robbie Elliott believes Newcastle will see a different player this coming season.
Robbie Elliott: “Santon’s obviously a good player, with a good background and came from a great club.
“It’s different in this country with how the game is played.
“Time will have helped him see how it’s played, and training with the players would have shown him how the Premier League is.
“Looking at left and right backs, it’s nice that Santon can play right or left.
“Danny (Simpson) has done a great job, he will be a miss if he leaves.
“He’s under-rated but no disrespect to the back line if you look at them it’s incredible how they’ve played as a unit.
“Jose (Enrique) was a very good player, and he had a great couple of seasons at Newcastle.
“We assumed he would be a huge miss, but Ryan (Taylor) came in and did incredibly well.
“It was one of the things where team spirit got bigger.
“With Pardew, if you played well you kept your place. I think that in a dressing room was a plus point – players had to play well to keep their places.”