Pope Francis flies to Cuba today for a three-night visit seen as a potential public relations coup for his hosts but also a risk, as he might speak more bluntly about democracy and human rights than the Communist government would like.
On the first papal visit to Cuba in 1998, Pope John Paul II made pointed comments about prisoners of conscience, saying they suffered "an isolation and a penalty" for merely wanting to "speak their mind".
Pope Benedict offered far more muted remarks about general prisoners in 2012.
This time, the Cuban government will welcome any papal denunciation of the US economic embargo of the island, but not a corresponding critique of Cuba's one-party political system that represses opponents.
"This is a Pope who has emphasised human rights wherever he has gone. I am confident he is going to do the same in Cuba," said Jean-Pierre Ruiz, theology professor at New York's St John's University.
Cuba is sensitive to criticism of its human rights record, saying it needs to restrain critics bent on destabilising the government.
Many of Cuba's dissidents receive funding from US-based organisations, and activists are routinely detained for demonstrating.
In a gesture to the Pope, Cuba released 3,522 prisoners last week, but none of the 60 political prisoners listed by the Cuban Commission of Human Rights and National Reconciliation.
One expert said the Pope may deliver a polite rebuke by speaking in general terms.
"We shouldn't expect a catalogue of Cuba's faults," said Candida Moss, theology professor at the University of Notre Dame.
"He may well focus his remarks on the global threats to human rights as a means of invoking the proverbial elephant in the room."
Some of Cuba's leading dissidents have said they will refrain from protest during the Pope's visit, respecting it as a religious event.