Plans are said to be being made for members of the royal family to stand in for the Queen during parts of Trooping the Colour for the first time in 70 years.
It is thought that Prince Charles, Prince William and Princess Anne may take the royal salute instead as the monarch continues battling mobility problems.
It is still hoped that Queen, 96, will still be able to attend part of the iconic ceremony at the Horse Guards Parade on June 2.
In the past the Queen has always been present for the duration of the military ceremony to mark her official birthday, either on horseback or in recent years seated on a dais.
The show of military pageantry usually lasts several hours including a parade down The Mall with the Household Cavalry and concluding with spectacular military flypast.
This year the spectacle also kicks off the long weekend of Platinum Jubilee celebrations.
Reports have suggested the Queen may travel from Buckingham Palace in a carriage to inspect the troops and will then retire, leaving Charles, William and Anne on horseback at the parade.
She would then reappear on the palace balcony for the flypast with other royal family members.
However her appearance could even be limited to the balcony, the Sunday Times reports.
It has previously been announced that the Queen’s presence at jubilee celebrations will only be confirmed on the day of each event.
Those joining her on the balcony will be limited to Royals currently undertaking official duties, meaning the Duke and Duchess of Sussex and their children will not join the iconic photo opportunity.
Prince Andrew will also not appear on the balcony.
The Duke of York was stripped of his military titles and agreed to no longer use HRH in January, amid his involvement in a civil sex abuse case with a victim of paedophile Jeffrey Epstein.
His lawyers concluded the case with a multimillion pound settlement with his accuser, Virginia Giuffre, although he denied any wrongdoing.
Five spectators were injured during a rehearsal for this year’s event.
Two were taken to hospital and three were treated at the scene after two parts of the grandstand gave way.
The rehearsal was stopped and the site was evacuated following the incident on Saturday.
