The Belgian forward established himself as one of the most direct dribblers in the Premier League last term, and made 32 appearances and contributed eight goals and assists for the Toffees, as they narrowly missed out on fourth place.
The versatile Belgium international often finds his best form in the big games, leading some to question his attitude in the smaller matches which Everton are expected to dominate.
However, it is a theory that Martinez does not subscribe to, and the Toffees tactician thinks that there is a strategic reason as to why the 26-year-old thrives in more open games.
The studious Martinez believes that there more to Mirallas's fluctuating displays than just the player's attitude, and gave his own theory to the Liverpool Echo.
“There are certain games that are harder for his ability, like if there is a lack of space,” said Martinez. “Kevin is a vital part of our squad. What he brings is quite unique and we haven’t got another player who can perform that role.
“It’s more difficult for him to show what he can do then. If the game is really eye to eye, then that’s where he is at his best. When spaces develop he’s a really intelligent player in the way he can hurt the opposition.
“If you play against teams that from the outside are seen as not as big games, what normally changes is the approach of the opposition. Normally they are more defensive minded and those sort of games are always harder for all forward players not just Kevin. But it’s a bit harsh to say he drops his level against lower opposition.”
Everton face a stern test of their capabilities on Saturday when they host Arsenal at Goodison Park.
The Blues hold Champions League aspirations, but the Gunners have designs on winning the Premier League, and both teams will be able to use Saturday evening's match as a good yardstick for their campaign.
Do you agree with Roberto Martinez’s assessment of Kevin Mirallas?