In Wigan's dual battle to beat relegation from the Barclays Premier League, where they take on fellow strugglers QPR on Sunday, and win the FA Cup, Kone has been a revelation of late.
Since returning from African Nations Cup duty in February, the Ivory Coast international has scored six goals in his last six appearances, with Wigan winning all the matches in which he has found the net.
Given the striker cost a reported £2.7million upon his arrival from Levante in August, that now appears to be money well spent.
Martinez could not be happier with Kone as he said: "We've been very impressed at how he has settled in this league.
"For any striker that comes into the Premier League it takes time for them to get to know the physicality and tempo of the game, but right away he adapted really well.
"We then lost him to the African Nations Cup for a long period, but since he has come back there's been this real feeling he has been making up for lost time.
"For me he's a sensational footballer, a very important player for us. I would say he has been invaluable for us.
"As a character he's very quiet, he has this interior calmness and an inner confidence that is quite impressive.
"On the pitch he has this knack of making the right decision when it comes to scoring a goal.
"He's experienced different environments, such as the German, Dutch and Spanish leagues, and to come into the British game now, it is probably at the right time of his career.
"Although he is enjoying the best moments of his career, the best is still to come."
Kone's form is likely to have alerted a number of bigger clubs, and given Wigan's reputation for being a stepping stone where players make their name before moving on, it would not be a surprise if the 29-year-old was poached this summer.
Martinez is far from concerned at the prospect, insisting as always when it comes to his players making the headlines, then should Kone leave it will be on the club's terms.
"Over the years we've learned not to focus on trying to keep players," added Martinez.
"We've been focused on bringing players in who can perform well for Wigan Athletic, to allow them to enjoy their football, and be as good as they can be for the duration they are going to be here.
"It's pointless for us worrying about what could happen if we lose him.
"We've made things clear we will never lose a player on the cheap, we'll never sell a player to balance the books because we don't have to.
"Of course, we'll never stop a player if they feel they have to move, but that will always be at the right price and the right time.
"So bearing that in mind, I'll never worry about losing a player.
"What I worry about is a player dropping their level of performance, but Arouna has been fantastic at this football club.
"Over the last six games he has been really consistent in what he has been doing, and that's rare to find.
"Initially we were delighted we were able to sign him, and now, for however long we are going to have him, we're going to enjoy him on a daily basis."
Ahead the trip to QPR, striker Callum McManaman has fully recovered from an ankle problem, with midfielder Fraser Fyvie the only new addition to the casualty list with "a knock" Martinez claims will keep him out for seven to 10 days.