The Briton returns to the scene of his brilliant victory 12 months ago, 75 points adrift of championship leader Fernando Alonso, and well aware that only a victory will keep alive his slim title hopes.
But he has already been given some bad news, with post-race investigations of his gearbox after the Singapore GP uncovering an identical gearbox problem to that which had put Lewis Hamilton out of the race.
McLaren has no option but to change Button's gearbox for a new one, which means he will moved down five places on the grid.
Hamilton will also be fitted with a new gearbox, but he will not suffer any penalty as he did not finish the last race.
McLaren technical director Paddy Lowe told AUTOSPORT: "Jenson's gearbox had the same problem as Lewis's gearbox during the Singapore Grand Prix, and subsequent investigation has revealed a terminal failure.
"Therefore both cars must start the Japanese Grand Prix with new gearboxes, which means that Jenson will receive a five-place penalty.
"Of course, this is a great disappointment for Jenson and the team. On the positive side, we have understood and completely resolved the issue, allowing both drivers to compete with confidence for podium positions."
Hamilton heads to the Japanese GP 52 points behind Alonso, with six races remaining in this year's title battle.
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