José Fernández was killed after a boat he was in made "severe contact" with a rocky jetty on Sunday (25 September) off the coast of Florida the US Coast Guard confirmed. The two other crash victims will not be named until their families are informed, the Coast Guard added.
Local Fire Rescue Chief Todd Garofalo, describing the scene of the crash to local news station WSVN, said: "They found a boat that was up against the jetties.
"They did do an initial search and they found three victims – two on top of the water, one underneath the boat and they had unfortunately passed away."
Though neither alcohol nor drugs are thought to have been involved, toxicology reports have yet to be carried out.
Fernández's team, the Miami Marlins, issued a statement paying tribute to Fernández, 24, on Sunday, in which they announced the postponement of their planned fixture against the Atlanta Braves that evening.
It said: "The Miami Marlins organisation is devastated by the tragic loss of José Fernández. Our thoughts and prayers are with his family at this very difficult time."
"He was one of our game's great young stars who made a dramatic impact on and off the field since his debut in 2013. Our thoughts and prayers are with his family, the Miami Marlins organisation and all of the people he touched in his life."
Players across the league expressed shock and sadness about the Cuban defectee's death. Top MLB player Mike Trout, who plays for the Los Angeles Angels tweeted: "Absolutely devastated hearing about José. Thoughts and prayers go to his family, friends, and Marlins org."
Fernández, 24, was drafted by Major League Baseball team, the Miami Marlins, in 2011. Widely regarded an upcoming star of the game, he was a regular on the club's starting rotation after coming back from elbow surgery in the 2015 season.
Just five days ago Fernández, who received US citizenship in 2015, shared a photo of his pregnant girlfriend on Instagram.
The picture was captioned: "I'm so glad you came into my life. I'm ready for where this journey is gonna take us together. #familyfirst."