The Belgium international, a late arrival from Chelsea on transfer deadline day, was ineligible for last weekend's victory over his parent club at Goodison Park.
However, his debut is likely to come at West Ham on Saturday and Martinez is confident the 20-year-old can surpass his impressive loan spell at West Brom, where he averaged virtually a goal every other league game.
"I have been very impressed with Romelu," said the Spaniard.
"We have seen him develop into a top striker from the outside: at 16 he came through the ranks at Anderlecht and all of a sudden you can see the potential.
"When you get to work with him you can see he is a very mature boy after his experiences.
"He is really intelligent with good football knowledge and above everything he has a huge desire to succeed and that is exactly what we need in the dressing room.
"What he brings is something we haven't got and that always excites you as a manager.
"Looking at what he did last season (scoring 17 in 35 appearances) he is capable of working and improving on that.
"That is our target. He is still very young and we hope it can be a perfect marriage over the next 10 months."
The availability of Lukaku and the return to fitness of Arouna Kone puts further pressure on Nikica Jelavic, who has started all four of Everton's league matches this season.
Jelavic is mired in a dreadful run of form which has seen him score just once (on March 16) in his past 25 matches for the Toffees.
Martinez insists he is not putting any extra pressure on the Croatia international but he expects increased competition - he also believes Kevin Mirallas can do a job up front despite playing most of his Everton career in a wide midfield role - to help.
"Niki has been working extremely hard and he should not be judged by the number of goals he has scored," said Martinez.
"If you look at the goal we scored against Chelsea it was a perfect header (by Jelavic) back into the six-yard area so his contribution was perfect on the day and it is about maintaining standards on the day.
"Every player wants to have as strong a squad as you can have because the competition is really demanding and you want to look around and see players that you know if you drop your standards you will lose your place to.
"Everyone is in that frame of mind. You want to be at your best, knowing you can help your team.
"We have Romelu to come back into the squad now and Arouna Kone to come back in after injury to join Nikica up front so we have three outstanding options for that position.
"Kevin Mirallas has also played in that position. When he played at Olympiacos he tended to play through the middle
"He brings you a different option up front with his pace and movement and knowing how to hurt the opposition he can be very valuable.
"You want competition for places, different types of players and different attributes that can help the team."