Two weeks before the 2015 season begins, the participation of McLaren-Honda's star driver is in doubt.
Team supremo Ron Dennis addressed the media in Barcelona on Thursday and admitted it is possible Fernando Alonso will not be in Melbourne.
Five days after the Spaniard's mysterious crash at the circuit last Sunday, Dennis insisted the British team is not "concealing" anything about the circumstances, not "protecting" the team or its driver.
It is amid an air of confusion and conspiracy about the crash, with rumours ranging from electrocution to seizure.
Dennis did admit that Alonso was briefly unconscious but he says that was because the car was blown off the circuit by a gust of wind.
Telemetry or video evidence was not presented, but Dennis did say McLaren had been in contact with a spectator who backed up the team's claim that heavy winds were swirling at turn 3.
He insists the telemetry proves McLaren's claim the KERS did not malfunction and electrocute Alonso, adding that medical tests on Alonso also agree.
But curiously, Dennis backtracked on the earlier news that Alonso was concussed, although admitted the driver has suffered a "loss of memory".
"The CT and MRI scans were completely clear, no indication of any damage," he said. "There was no concussion detected in the scan and physically he is perfect."
He said Alonso is therefore keen to be testing this week, but has been sidelined on the advice of doctors.
"The doctor said if you really want to be sure, and you want to give him the best chance of going to Australia then the best thing to do is to rest him."
But Dennis also admitted whether or not Alonso will be racing in Melbourne is currently "unquantifiable".
"I can't foresee any reason why not, but I'm not the doctor," he said.
"There will be some tests, there are processes laid down within the FIA, and I can't see any reason why he won't sail through. But it's not for me to determine."
As for the media intrigue, and the apparently unnecessary three-night hospital stay, Dennis speculated that the "level of focus was extreme because Fernando is Fernando".
He also said doctors are generally being "super cautious" about blows to the head in sports, even though the accelerometer in Alonso's ear showed a lower than 15G impact.
"He is completely lucid and normal. He is devoid of injuries. There was no injury, there was no electrocution."
The leading conspiracy theory at present is that some sort of seizure may have caused Alonso to crash.
Former F1 doctor Gary Hartstein said on Twitter: "Gut feeling? He's had a medical problem that caused him to stop his car. I hope that's not the case."
Dennis did not completely rule that out, but said McLaren has "no data" to support the theory.
He said Alonso suffered memory loss but, amazingly, Dennis admitted to not actually asking the Spaniard his opinion about what caused the crash.
"I haven't had that conversation with him yet," said Dennis. "There's a time and a place."