As a teenager he tried three times, unsuccessfully, to defect from Cuba, once spending a month in Cuban jail. He finally escaped to Mexico on his fourth attempt, saving his mother from drowning on their boat trip over.
He and his mother were then reunited with his father in Tampa, Florida where he had fled two years earlier.
But Fernandez's transition from his life in Cuba was difficult. Baseball helped him acclimate to his new American life.
After starting at Alonso High School in Tampa, speaking almost no English, Fernandez steered the baseball team to two state championships.
He was drafted by the Marlins in 2011 at 20 years old and named National League Rookie of the Year in 2013.
The Miami Herald reported his grandmother, a loyal supporter, often stood on her roof in Cuba during his games to listen to the sports radio broadcast as her grandson played.
Players and fans described him as enthusiastic, energetic and charismatic. Many Cubans from Miami's Latin community, felt that the player embodied their own struggles.
Miguel Garay, 78, a Miamian who came from Cuba's Pinar del Rio said: "His story was our story.
"There's such a great tradition of baseball in Cuba and he embodied it better than anyone."
After undergoing surgery in 2014 for a torn elbow ligament Fernandez became a US citizen in 2015, where he gave the keynote speech at his citizenship ceremony.
He said: "This is one of my important accomplishments. I'm an American citizen now - I'm one of them. I consider myself now to be free."
Fernandez was described as an "avid fisherman" and was aboard a friend's boat when the vessel hit a jetty, causing it to capsize.
He had revealed recently that his girlfriend was pregnant.
Marlins President David Samson said at a news conference: "When you talk about tragedy like this there are no words that come to mind.
"There is prayer and thought toward his family and his soon to be born daughter. You recognize how precious life is."

University Hospital Coventry is undergoing remedial work because its structures "were not as robust" as originally planned.
The hospital trust says interim safety measures are in place during the work.
Skanska, which built the hospital under a private finance initiative (PFI) scheme, declined to comment.
More reaction to the story
David Eltringham, chief operating officer at University Hospitals Coventry and Warwickshire NHS Trust, said: "We can assure our patients, staff and visitors that we remain vigilant in ensuring fire safety standards are maintained at all times."
He said the trust "learned of some potential issues with the infrastructure" which prompted the internal investigation.
The investigation found that "in the unlikely event of a fire, the structures to prevent it spreading were not as robust as those specified in the original plan for the building", Mr Eltringham added.
The trust says it collaborated with Skanska to identify remedial work and is working with the fire service to optimise fire safety standards.
Meanwhile, steps are being taken to strengthen fire safety including additional patrols and increasing rubbish collections.
A West Midlands Fire Service spokesman said: "We are working together with University Hospital Coventry and have an action plan in place for upgrading fire standards."
Construction firm Skanska, which was paid to build the hospital, said it had nothing further to add to the statement issued by the trust.
Jose Fernandez, the talented 24-year-old baseball star who died in a boat crash on Sunday, was heralded by baseball commissioner Rob Manfred as one of the game's "great young stars".
[NEXT_CONCEPT]
A £380m hospital which opened 10 years ago may have been constructed without adequate fire protection, a safety review has revealed.