Mar.4 (GMM/ Fernando Alonso says he can “understand” why he has been sidelined for the Australian grand prix.

McLaren on Tuesday announced that, on the advice of the Spaniard’s doctors, the risk of ‘second impact syndrome’ means the 33-year-old will sit out the first race of the new Honda-powered era.

“It will be tough not to be in Australia,” Alonso told his followers on Twitter, “but I understand the recommendations.

“A second impact in less than 21 days ‘NO’,” he said. 21 days after Alonso’s February crash would be 15 March — the day of the Melbourne race.

The 21-day issue is a pertinent one. Protocol in sports such as rugby dictates that concussed athletes not play again for at least 21 days.

Lotus driver Romain Grosjean told RMC Sport that, although Alonso’s crash did not seem to be particularly heavy, fully lateral impacts are “extremely rare”.

“Almost always you crash with some sort of angle,” said the Frenchman, “resulting in damage.

“But when you hit the wall completely parallel, and the car does not break, suddenly all of the energy that is supposed to be absorbed by the carbon is absorbed completely by Fernando,” he added.

Former F1 driver Patrick Tambay agrees, even if McLaren argues that Alonso is completely uninjured.

Referring to Alonso’s advice to sit out Melbourne, the former Ferrari driver said: “It is a wise recommendation.

“Doctors tend to protect themselves as well, because in the case of another accident, they might be responsible for what happens.

“At the same time, on technical and sporting terms and what we have seen so far, it’s really not a big loss for Alonso to be on the safe side physically and then return fully fit later on,” Tambay added.

Alonso will be replaced in Melbourne by McLaren reserve Kevin Magnussen.

“Shame about the circumstances,” the Dane wrote on Twitter, “but still I’m so excited to be racing in Melbourne. Can’t wait!”

Alonso replied: “Best of luck at the race mate!”