MIAMI -- The Marlins are set to start Spring Training on Wednesday with 66 players, including 35 pitchers. Before taking the field for the first time at the Roger Dean Chevrolet Stadium complex, MLB.com breaks down each position and predicts which 25 will be on the Opening Day roster.
Catcher (2):Jorge Alfaro, Chad Wallach
Acquired from the Phillies as part of the J.T. Realmuto trade on Thursday, Alfaro will hit the ground running, having to learn a new organization and the pitching and coaching staffs. The other catcher on the 40-man roster is Wallach, who actually was Miami's Opening Day and closing-day catcher in 2018. Wallach is a defensive catcher who grades extremely well in pitch-framing metrics.
:: Spring Training coverage presented by Camping World ::
First base (2):Peter O'Brien, Neil Walker
Nothing is guaranteed for O'Brien, a South Florida native who made the most of a September callup last year, belting four home runs and driving in 10 that month. Walker, a free-agent signee, is a left-handed-hitting option who came up as a second baseman with the Pirates.

Second base (1):Starlin Castro
A four-time All-Star, Castro enters his second season with the Marlins, and he projects to hit in the middle of the order, perhaps third. Castro had 32 doubles, 12 home runs and 54 RBIs last season. If he has a strong first half, he could become a potential trade candidate.
Third base (1):Brian Anderson
Although he played 71 games at third base compared to 91 in right field in 2018, the Marlins will enter Spring Training with Anderson as their third baseman. Perhaps that will change depending on the health of Martín Prado, but for now, Anderson is getting the nod.
Shortstop (2):JT Riddle, Miguel Rojas
This is a big camp and season for Riddle, who had left shoulder surgery in 2017 and was limited to 102 games last year. He is hardly a lock to get a majority of the time at shortstop, with Rojas coming off a solid season in which he hit .252 with 11 home runs and 53 RBIs.

Outfield (4):Lewis Brinson, Austin Dean, Rosell Herrera, Curtis Granderson
After a sluggish rookie season in which he batted .199 with 11 home runs and 42 RBIs, Brinson is expected to get every opportunity to be the regular center fielder. But he may be on a shorter leash this year. Herrera, a switch-hitter who played briefly for the Reds and Royals last season, will get a chance to win a starting spot. Dean was promoted to the big leagues last August and saw regular time in left field. Although Granderson is a non-roster invitee, the veteran outfielder is an option to platoon in left field.

Starting pitchers (5):José Ureña, Dan Straily, Wei-Yin Chen, Sandy Alcantara, Trevor Richards
For the second straight season, Urena projects to be the Opening Day starter. The right-hander stepped up in the second half last year and finished with a team-high 31 starts and 174 innings. Straily and Chen are veterans with track records who add experience that will help take pressure off an inexperienced group of starters. Alcantara and Richards both were rookies in 2018 and each showed promise, as well as predictable struggles.
Relief pitchers (8):Drew Steckenrider, Adam Conley, Tayron Guerrero, Riley Ferrell, Jarlin García, Jose Quijada, Sergio Romo, Austin Brice
The closer spot in Miami's bullpen is up for grabs, with Steckenrider the early frontrunner to handle the role. But the team may also go by matchups, and Conley is a left-handed option. Guerrero is the hardest thrower of the unit. Garcia is another left-handed option, and Quijada is looking to make the jump from Triple-A to be another lefty relief candidate. Romo, who has agreed to a one-year deal, according a source, would fill Miami's need for a veteran arm to complement a young bullpen. The club has not confirmed the deal, which is pending a physical.
In the second year of the building process, manager Don Mattingly and his staff once again will be working with a mostly inexperienced squad filled with players who are continuing to gain Major League experience.
• Staying the course remains Marlins' vision
CATCHERS
C Jorge Alfaro
C Chad Wallach
INFIELDERS
1B Peter O'Brien
2B Starlin Castro
SS JT Riddle
3B Brian Anderson
OUTFIELDERS
LF Austin Dean
CF Lewis Brinson
RF Rosell Herrera
UTILITY PLAYERS
INF Miguel Rojas
INF Neil Walker
OF Curtis Granderson
STARTING PITCHERS
RHP Jose Urena
RHP Dan Straily
LHP Wei-Yin Chen
RHP Sandy Alcantara
RHP Trevor Richards
RELIEF PITCHERS
RHP Drew Steckenrider
LHP Adam Conley
RHP Tayron Guerrero
RHP Riley Ferrell
LHP Jarlin Garcia
RHP Austin Brice
LHP Jose Quijada
RHP Sergio Romo
INJURED LIST
LHP Caleb Smith (lat surgery)
RHP Pablo López (shoulder)
1B/OF Garrett Cooper (right wrist)
RHP Julian Fernández (Tommy John surgery)
3B Martin Prado (Hamstring, knee, oblique)