"To all my fans: you deserve to know that today, along with my family, I made the decision to undergo Tommy John surgery," Fernandez wrote in the Instagram post. "It was not an easy one, but with my condition it is the only option where I can return to the game I love as the same player I am temporarily leaving the game as.
"I’ll be back as soon as my elbow will let me . And if anything… I have about a year to learn how to throw lefty ;)You haven’t seen the last of me Miami, I promise you that."
Veteran southpaw Randy Wolf, who signed a one-year deal with the club on Wednesday, has had the Tommy John procedure twice.
Wolf missed the 2013 season to recover from it before pitching for Triple-A Reno of the Arizona Diamondbacks organization this year. He and the Marlins agreed to a contract after he used his opt-out clause. In his return to the big-league mound on Wednesday, Wolf collected his first career save in 15 years in the majors.
"It’s definitely unfortunate for him, but at the same time at 21 years old — trust me, I’ve been there, I’ve done it a couple of times," Wolf said. "If he does his rehab right, he’s smart and he has a slight OCD with his program he’ll be back to the dominant pitcher he is."
Fernandez, 21, was 4-2 with a 2.44 ERA in eight starts this season. In his last start on Friday against the Padres in San Diego, he gave up six runs (five earned) over five innings. Continuing discomfort cancelled his scheduled bullpen session on Sunday.
The reigning National League Rookie of the Year tossed a career-high 114 pitches in his previous start against the Dodgers in Miami.
During Fernandez’s rookie season, the organization set an innings limit. He finished with 172 2/3 innings, which set a career high.
"He’s fun to watch," president of baseball operations Michael Hill said prior to Wednesday’s game at Dodger Stadium. "We’re fans of the game. We appreciate and respect the game and have a passion for the chosen work in this industry. When you see someone that embodies that passion and energy you want to root for him because he’s enjoying what he’s doing. Not even every fifth day, every day he came to the ballpark having fun with his teammates helping us win games. Now he’s going to have to do it in a different capacity for the next 12-18 months."