Lewis Hamilton's championship hopes suffered another big blow on Saturday after he was given a penalty for changing his car's gearbox.
The British driver, who has not scored in the previous two races, will require a gearbox change ahead of tomorrow's qualifying.
"In P3 today, we noticed abnormal gearbox oil pressure on Lewis's car, which we believed we had corrected ahead of this afternoon's qualifying session," said a McLaren spokesman.
"This afternoon, as we fired up Lewis's car several times in preparation for qualifying, we became aware that the symptoms were worse than we'd originally diagnosed, and a decision was later taken to change the gearbox ahead of tomorrow's qualifying session and the grand prix.
"As a result, Lewis will receive a five-place grid penalty for tomorrow's race."
The grid-deciding session will take place on Sunday - five hours ahead of the start of the race - after officials were forced to cancel today's qualifying because of the poor weather.
Hamilton, 20 points behind championship leader Mark Webber with four races to go, has endured a tough weekend at Suzuka so far, having crashed out on Friday and having managed just six timed laps so far.