The Chelsea player impressed coming off the bench for West Brom last season and he scored his first goal for Everton having started as a substitute in the 3-2 win at West Ham on 21 September.
But Martinez is convinced the 20-year-old's all-round game is good enough for him to secure a regular starting berth.
"I think every team is different and the options that you have in that team are different," said Martinez.
"Romelu now, at his age, has had enough experience. When you score 17 goals in this league you mature a lot, and quickly, and I do feel that Romelu is ready to start.
"He's not an impact player and he's not someone who needs to come on when games are open, his overall game is good enough to start games and affect games from that point."
Everton host Newcastle in Monday Night Football, knowing a win would send them into the Premier League's top four.
The Toffees have only scored six goals in the campaign thus far, with two of those coming from the boot of Leighton Baines, but Martinez is sure he has the firepower necessary as the club looks to match or improve upon their sixth-place finish last season.
"You look at the options in that position, it's exciting," said the Spaniard. "We've got Arouna Kona, Nikica Jelavic and Romelu Lukaku. It's as good as it gets.
"We're really, really pleased to have a position here where it's going to be very expensive to play. That develops great competition and it raises the standard."
Everton v Newcastle is live on Sky Sports 1HD at 7pm