The 27-year-old was withdrawn in the first half of his side's 1-1 draw at Liverpool after picking up an ankle injury.
While the extent of the injury is as yet unknown, Pardew is worried that he could be without the former Nottingham Forest man for a while.
"Perch's injury looks serious. He is the type that would play through but there was no chance of that and it doesn't look too good," said Pardew.
The Magpies will also be without captain Fabrico Coloccini for the next three games after he was shown a red card during Sunday's game for violent conduct.