The Argentina legend has backed his countryman to fire his former club to domestic glory next season
Rafael Benitez's side finished third in 2013-14 behind winners Juventus and second-placed Roma, but lifted the Coppa Italia with a 3-1 win over Fiorentina.
Higuain joined Napoli from Real Madrid in a €40 million deal last summer and enjoyed a fine first season at the club, scoring 22 goals in 42 games, and Maradona has applauded his continued improvement.
The former Argentina coach said: "I told him in 2010 to focus hard on his skills as a striker. I have seen him grow and become a champion.
"When in form, Gonzalo makes a difference. Higuain must not only win the Scudetto with Napoli, but score the goals that can help win the World Cup with Argentina."
Maradona added that the striker's input alone would not be enough next season and urged Napoli to further bolster their squad in the summer.
He said: "Higuain on his own cannot win trophies. Something is still missing. The president [Aurelio de Laurentiis], must do some more tweaking in the market."