The Netherlands international is in danger of recording the worst run of his career due to only being able to score once in his last 11 appearances.
Van Persie's poorest term came back in 2006 when he went 13 matches with just one goal under his belt during his time at Arsenal.
"Having a barren spell has got to happen," Cole told the Manchester Evening News. "As a centre-forward you know it will happen at some point. You just have to keep faith with yourself.
"He is established over here and is coming to a very good team so everyone knows he is going to score goals and he has done that. Nobody is surprised.
"Now he has one in 11, that is going to happen. He has had a purple patch now they've dried up and he will score again. There isn't much you can do to change it. You just know it is going to come back."
Liverpool striker Luis Suarez has since taken over from the Dutchman as top scorer in the Premier League.