But series organisers have now moved the Fuji date -- making it clash instead with races that affect other drivers on the world endurance circuit.
"It's a shame that a race is changed for one driver when the change hurts so many other drivers who have contracts in place," Alonso's former teammate Jenson Button, now a Super GT driver in Japan, said on Twitter.
Sports car driver Olivier Pla added: "Many thanks WEC, your lack of consideration and respect for the drivers who had a contract the same weekend is unbelievable.
"I'm sure I will be not the only one to be (not) impressed with what you did."
And Andre Lotterer said: "Wouldn't it have been a lot easier for everyone if Alonso would just miss a F1 race? Is that going to change much for him?"