The Spanish coach spoke glowingly of the 19-year-old, who is on a season-long loan from Barcelona.
Deulofeu was impressive against Stevenage in the League Cup, in which he scored the equaliser in a 2-1 victory at Goodison Park.
Martinez hinted that Toffees fans will get to see more of the teenager, who came on as a substitute in Everton's last Premier League game against Cardiff City, as he progresses in training.
"He is a player we could see more of in the coming weeks," Martinez told EvertonTV. "Gerard is a player with great application in his work and already you can see that he is growing into a phenomenal footballer.
"He is only 19 and he is relying on his natural talent. Coming from Spain and a specific way of playing at Barcelona, it is going to take time to adapt, and he is doing that quicker than I expected.
"In the League Cup he showed he is someone who can create something from nothing. When you can do that it gives you an extra edge in the final third. Clearly he is well ahead of where I expected him to be at this stage."
Recent reports suggested that Barca may allow Deulofeu to spend next season at Everton.