Everton team mate Marouane Fellaini.
The Belgian midfielder has scored five goals in Everton’s opening nine league fixtures and is enjoying what is arguably his best season at Goodison Park since arriving in 2008.
Mirallas insists the 24-year-old is still improving and that Everton fans can look forward to more strong performances in the future.
He told Everton’s official website: “We know he is a really vital player for us and let’s hope this excellent form continues.
“When it comes to the big vital games he is always there and we can rely on him to come up with a big performance.
“You only had to look at his second goal at Fulham on Saturday. He basically made it and scored it all on his own. It was a fantastic effort.”
The striker also believes Fellaini’s age works in his favour and that his progress in his four years at Everton has been outstanding.
“It’s four years now that he has been here and I think in that time you can see how much he has come on as a player,” he added.
“He has really made good progress. He is about to turn 25, so I think he has still got plenty of chances to improve even more.”
The forward has just one Premier League goal to go with his brace against Leyton Orient in the Capital One Cup so far this season.