Jol believes the 31-year-old Croatian can play a big part for the Whites this term.
He told fulhmfc.com: "If you look at strikers, Petric is in a group of players who will score goals.
"Maybe not 20 in 20 games but he will score one every two or two and a half games. That is a good record.
"Petric was not only excellent in his finishing, he was good on the ball as well. The Barclays Premier League doesn't give you much time on the ball and he did well to keep the ball for us."