The Mexican international made the revelation following his country's 3-1 win over Croatia last night, which in turn set up a last-16 clash against Van Persie's Holland at the World Cup.
"Robin is a great centre-forward. He's got incredible technique which makes him world class, while he's one of the quickest strikers around. I've learned a lot from him and he's helped me so much," Hernandez told FIFA's official website.
The upcoming encounter will also see Hernandez come up against Dutch head coach Louis van Gaal, who will take charge of United after the tournament.