The Spaniard arrived at Goodison Park in the close-season and has overseen a run in which Everton have lost just once in their opening 10 league matches, leaving them in seventh place and only a point behind Chelsea in second.
Martinez has also begun to change Everton's style of play, and he is confident that once they reach their full potential they can challenge for a UEFA Champions League place.
"We need to find a way to break into the top four," he said ahead of Saturday's trip to Crystal Palace. "How long it takes I don’t know.
"I feel that the league is really competitive, every team wants to win.
"That creates big surprises and an increased level from every team.
"I don’t feel we've fulfilled our potential as a squad yet, when we do the perception will be really positive."
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