Pope Francis has fuelled the rumour mill with a postponed Africa trip and the curious timing of an upcoming meeting of cardinals. The speculations were renewed by the announcement about his proposed travel to L'Aquila in central Italy in late August - similar to other popes who have retired.

Speculations arose in early May after the 85-year-old appeared in public using a wheelchair for the first time due to pain in his knee.

The 85-year-old cancelled his proposed Africa trip in July due to forced use of a wheelchair.

"At the request of his doctors, and in order not to jeopardize the results of the therapy that he is undergoing for his knee, the Holy Father has been forced to postpone, with regret, his Apostolic Journey to the Democratic Republic of Congo and to South Sudan, planned for 2 to 7 July, to a later date to be determined," Matteo Bruni, the director of the Holy See Press Office, said in a statement recently.

The speculation gained momentum after Pope Benedict made the unusual decision to host a consistory on August 27 to create new cardinals, some of whom will be eligible to elect the pontiff's successor.

"It's very odd to have a consistory in August, there's no reason that he needs to call this three months in advance and then go to L'Aquila in the middle of it," Robert Mickens, the Rome-based editor of the English-language edition of La Croix, a Catholic daily newspaper, was quoted as saying by The Guardian.

Most recently, in May, Pope Francis had joked about his knee during a closed-door meeting with bishops: "Rather than operate, I'll resign."

In July, he is expected to go on a trip to Canada and that schedule remains unchanged for now. He continues to receive injections in his knee and physical therapy, according to the Vatican.

In July 2021, the pope underwent intestinal surgery, which kept him in the hospital for 10 days.

What is the protocol if the Pope resigns?

If that happens, the cardinals will gather together to name a successor. The College of Cardinals, which elects the next pope, is made up of Catholic Church's most senior officials.

Who was the last pope to resign?

Benedict XVI, Pope Francis' predecessor, resigned in February 2013 over health concerns. He was the first pontiff to resign in around 600 years.

Vatican watchers, however, say a resignation seems unlikely. Rumours within the insular Roman Curia - the Catholic Church's powerful governing body - are nothing new, and often fuelled by those with an interest, said Italian Vatican expert Marco Politi.

"These rumours are encouraged by the pope's opponents who are only eager to see Francis leave," he told new agency AFP.