Everton boss Roberto Martinez confirmed at a press conference on Wednesday that Kone requires surgery on his knee and is unlikely to play again this season.
The Ivory Coast international had already made a slow start to life at Goodison Park, failing to score in his first three appearances, before missing the whole of September with a knee injury.
He returned at the start of last month but another knee injury picked up against Hull on October 19th has proven worse than initially feared.
"We had to send him for a surgery and we need to see how long exactly he'll be out but it'll be a while. I would say the worst fears were confirmed and he had some loose cartilage in his knee. We'll know in the next 48 hours.
"He needs it repaired and the loose cartilage taken out. It takes a long time to recover. We'll need to see how he gets through surgery but it's a really difficult injury in terms of time.
"He'll be fine long term but it's disappointing because I felt he showed against Hull he was ready to be himself and enjoy his football.
"We'll make sure he gets back fit and strong as ever."
While some may cheekily suggest the injury is a blessing in disguise given Kone's poor performances so far it does mean that Lukaku and the continually mis-firing Nikica Jelavic are now the club's only two fit senior strikers, with Martinez also confirming that the Belgian had taken part in training despite limping off against Spurs last week.
The on-loan striker has been fantastic so far this season but he cannot be expected to do it all on his own, particularly with the busy festive period on the horizon. Jelavic, now more than ever, needs to somehow re-discover his early Everton form (and stay injury free) if the club is to achieve its ambitions this season. Either that or someone can find the cupboard Velios is hiding in and throw him out onto a football pitch.
For Kone it of course means a frustrating spell on the sidelines, but the injury is one he should recover fully from. However, the former Wigan man, who cost Everton £6million, will be 30 by the time he is playing again and you must question the wisdom of the move given Everton's poor financial resources, even before this injury and the advantage of hindsight.
Most of Everton's rivals would turn to the transfer market to ease such an injury crisis in the January transfer window and all eyes will again switch to Bill Kenwright as we move into 2014.
But given Everton's previous form in the winter window I wouldn't get your hopes up over any extra striking additions, with 'keeping what we have' almost certainly the priority.