Our former full-back will take over at Wisla in January - replacing caretaker boss Tomasz Kulawik.
Petrescu said: "I'll show my players new things because I still have good fitness," said the 37-year-old.
"Regarding communication, I will have a translator and I will learn Polish in the coming months."
Wisla, who have won the Polish title for the last three seasons, are top of the league standings after earning 32 points from their opening 16 matches.