The Queen was forced to miss church as she rested on doctors’ advice, according to reports.
Her Majesty had been due at All Saints Chapel in Windsor but was said to have missed the service.
It comes after the 95-year-old monarch spent a night in hospital for tests last week and was forced to cancel a visit to Northern Ireland but it is said that she will now be accompanied by one of her children or grandchildren for engagements in the future.
Queen Elizabeth will be joined on future public visits by another member of the royal family to avoid letting people down in case of health scares.
Members of the royal family had already increased the number of engagements they carry out with The Queen following the death of Prince Philip in April and the role will become even more important following the monarch's health scare.
A royal source said that both Prince William and Catherine, Duchess of Cambridge, are "keen to provide any support they can".
The monarch is pressing on with "light duties" following her stay in hospital and another source said that The Queen is "knackered" following a busy period over the last month where she had undertook 19 engagements.
A source told The Times newspaper: "She is knackered."
Royal insiders explained that her private schedule has been full with "a constant flow of lunches and dinners with family and friends, because the Queen does not want to dine alone".
It is also reported that palace aides may "discreetly keep an eye" on The Queen's late night TV viewing habits as she is said to be a big fan of the BBC crime series 'Line of Duty' and also stayed up to watch Emma Raducanu's historic US Open win last month.
Royal historian Hugo Vickers said: "The problem is that the Queen does not want to disappoint people.
"She can say no to people, but by and large she doesn’t. What you’ve got to do is pace her."