Newcastle have quashed rumours David Santon's knee problem can be traced back to injury woes earlier in his career.
Santon has been ruled out of Saturday's game against Aston Villa in news which will frustrate manager Alan Pardew, who had hoped to blood his new arrival.
Santon damaged his right knee in training and has undergone a scan to assess the extent of the injury.
But while the fresh setback is disappointing, Newcastle insist he was completely fit when he had his medical over the summer.
"Newcastle United can confirm that Davide Santon sustained an injury to his right knee during training yesterday which will keep him out of Saturday's match with Aston Villa," a club statement said.
"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."