The Argentine may miss the next three matches if he can't shake off the troublesome muscle injury.
But Pardew has faith in Perch, he told the Evening Chronicle: "Coloccini is the one to worry about.
"I don't think he's going to make next Sunday against Liverpool.
"We have to really hope that it isn't a bad hamstring pull. He will certainly miss the next two or three games and that's when you need somebody like Perch who was phenomenal at left-back and then centre-back."