F1 teams are looking into how to improve the safety of the chassis following the crash that killed Formula 2 driver Anthoine Hubert.
Juan Manual Correa is also struggling to recover from a 17 hour operation in London to save his right leg following the Spa crash.
"The subject will be discussed at the next meeting of the technical working group," he added.
Green said the biggest changes will be made for 2021, but added: "Everyone is aware of what can already be done for 2020."
However, he also said that in incidents as severe as the Hubert-Correa crash, there is a limit to what can be done as "the energy involved was absolutely huge".body check tags ::