It was from the bench that the Belgium international announced himself to the Toffees faithful last weekend in a goalscoring cameo on a debut which helped turn the tide in his new side's favour against West Ham.
The 20-year-old was often deployed as a substitute during his time with West Brom last season too, and he signed off at the Hawthorns by coming on to score a second-half hat-trick in a remarkable 5-5 draw with the already-anointed Barclays Premier League champions Manchester United.
Lukaku started 20 times for the Baggies in the league but appeared as a replacement in a further 15 games as his combination of size, speed and athleticism posed a unique challenge for weary defenders.
However, while some strikers have forged a career making impacts in the latter stages of games, Martinez is adamant the Chelsea forward can influence contests from the very first whistle.
"I think every team is different and the options that you have in that team are different," said the Everton manager.
"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.
"But you look at the options in that position, it's exciting. 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."
Martinez sees similar strength in depth in Everton's opponents on Monday night Newcastle.
A lack of activity during the summer transfer window coupled with a 4-0 thrashing at the hands of Manchester City in their first game left some Magpies fans fearing the worst this season.
However, Martinez believes Alan Pardew's men will pose a serious threat to the Premier League's only remaining unbeaten record at Goodison Park.
"I see a really good balance between experience and organisation but then a real threat with the likes of (Loic) Remy, (Papiss) Cisse, (Hatem) Ben Arfa and (Yohan) Cabaye," added Martinez.
"You're talking about top, top footballers who are in a good moment in their careers and full internationals.
"You take away the Manchester City game and they've been performing at a very, very good level so it would be foolish for anyone to underestimate the potential of this Newcastle side."