So far, the larger-than-life retired Cuban leader has made no public comment on the biggest news in years — that the U.S. and his island nation will restore diplomatic relations after more than 50 years of hostility.
His brother, President Raul Castro, announced the historic shift in a surprise television appearance Wednesday and there was speculation he could address it again during the Cuban National Assembly, which started one of its twice-annual sessions Friday.
Among those speaking out on the topic was Raul Castro's daughter, Mariela Castro. She said moves by President Barack Obama to ease some travel and trade restrictions with the island are welcome but won't lead to the downfall of the communist system.
"If the U.S. thinks these changes will bring Cuba back to capitalism and return it to being a servile country to hegemonic interests of the most powerful financial groups in the U.S., they must be dreaming," she told The Associated Press.
But it's her famously bearded uncle who has long personified the Cuban revolution and its defiance of Washington. And he's not known for being reticent. He once set a record for the longest speech at the U.N. General Assembly — 4 hours and 16 minutes — and he's been known to weigh in on such topics as the Israel-Palestinian conflict in lengthy editorials.
When he suddenly went silent in 2011, there was speculation about the health of the elderly former leader, and now there is again.
Writer and Cuba expert Ann Louise Bardach says rumors swirl that the 88-year-old Castro never fully recovered from a series of surgeries that prompted his retirement.
"Even if he were in perfect health, he's of a certain age," said Bardach, author of "Without Fidel" and "Cuba Confidential."
Another explanation is that Fidel Castro is staying out of the limelight because, officially at least, his brother runs the country. Government officials won't discuss such a sensitive issue, and many ordinary Cubans shrug it off.
"He'll come out later," 19-year-old English student Enriqueta Nieto said of Fidel Castro. "But I think he's fine."
Obama said Fidel Castro's name came up only briefly in his phone conversation this week with Raul. The U.S. president said he opened the call with a 15-minute statement, then apologized for talking so long.
Obama said Castro responded, "You're still a young man and you still have a chance to break Fidel's record. He once spoke for seven hours straight."
The U.S. president said the Cuban leader then delivered an opening statement at least twice as long as his. "I was able to say it runs in the family," Obama quipped.
It's not clear if Raul Castro brought up restoration of relations at Friday's National Assembly session, which was not open to the public.
On the midday newscast, there was no mention of any discussion of U.S. relations. State TV reported the economy minister, Marino Murillo, gave an update on moves toward eliminating Cuba's unwieldy dual-currency system, which since 1994 has created two pesos: one roughly pegged to the dollar and another, worth about 1/25th the convertible currency, which most ordinary Cubans get paid in. The bi-annual session was expected to resume Saturday.
For years after he left office in 2006 due to illness, Fidel Castro penned editorials, called "Reflections," that dutifully were printed in official media and read verbatim on state TV newscasts. In October 2012, he said he was retiring as a columnist, but has since published occasional opinion pieces to comment on world events.
The elder Castro rarely appears in public these days. He last was seen on Jan. 8 when he attended an art exhibition in Havana. The last official photos showed him meeting in July with Russia's President Vladimir Putin and China's President Xi Jinping in Havana. In August, Venezuelan President Nicolas Maduro said he met with him and showed photos of their encounter. His last written commentary, about Cuba's efforts to fight Ebola, was in October.
Still, it's not entirely unusual that Castro has yet to weigh in on this week's news. He waited six days before commenting last year on the death of Hugo Chavez, the Venezuelan president who was a close friend and ally.
And it's possible the former president is just slowing with age.
"I think that Fidel is a little bit older and his activities are very limited, that's for certain," said Maria Teresa Ojito, a 66-year-old language teacher.
But, she said, "I'm not very worried because Raul is the one who's running the country. ... Really, the one who has to make decisions these days and enter into dialogue is Raul, not Fidel."
Pedro Pablo Rodriguez who, like Castro, is retired, also points to his age. "He's older and he's likely very excited about these things," the 80-year-old said. "Possibly, we just have to wait until he recovers, but I'm sure he will be fine because he's a strong man."