The double Formula One world champion was handed a 20-second penalty after he braked unusually early into turn six at Albert Park on the penultimate lap, with Mercedes driver Russell close behind and losing control.
Russell ended up with his car on its side in the middle of the track, the driver calling urgently for the race to be stopped.
Aston Martin team boss Mike Krack said in a letter to fans on social media on Tuesday that while everyone was relieved Russell walked away unhurt, "I want you to know that we fully support Fernando.
"He is the most experienced driver in Formula One. He has competed in more Grand Prixs than anyone else and has more than 20 years of experience. He is a multiple world champion in multiple categories.
"To receive a 20-second time penalty when there was no contact with the following car has been a bitter pill to swallow, but we have to accept the decision," he added.
"We made our best case but without new evidence we are unable to request a right of review."
Krack added that Alonso had been "using every tool in his toolbox" to finish ahead of Russell and said the Spaniard would "never put anyone in harm's way."
