He recently left the US for Europe to climb the single seater ladder to formula one.
"I think in two or three years, Pietro should get to formula one," 67-year-old Fittipaldi, whose brother Wilson and nephew Christian also raced in F1, said in Sao Paulo on Tuesday.
"It is very difficult, but he is well supported and very dedicated," he added.
"He is doing well this year in British Formula Renault and also went very well in Nascar," Fittipaldi is quoted by Brazil's Globo.
The report said Pietro is part of the Telmex-headed Mexican driver programme that has already paved the F1 careers of Sergio Perez and Esteban Gutierrez.
"Pietro is in a very good programme," confirmed Fittipaldi, "the same as Perez and Gutierrez, which is very structured and will help Pietro to get to formula one.
"He is doing everything right to achieve this great goal," he added.