Alan Pardew revealed on Thursday that the 20-year-old former Inter Milan full-back was undergoing a scan after damaging his right knee in training.
NUFC statement: "Newcastle United can confirm that Davide Santon sustained an injury to his right knee during training on Thursday which will keep him out of Saturday's match against Aston Villa.
"The player had a scan on Thursday afternoon and will undergo treatment over the weekend and will be reviewed by a specialist early next week.
"Davide was injury-free when he completed his pre-signing medical examination and scans. The injury he sustained on Thursday is not connected to his previous injuries."