MIAMI — It could take a while before we truly know if the Marlins’ decision to trade Zac Gallen for shortstop prospect Jazz Chisholm will pay off.

Losing Gallen meant losing a potential starter who could have played a key role in bringing the Marlins closer to contention in the coming years.

Yes, Miami is deep when it comes to pitching. But there is plenty of risk with almost all of the franchise’s pitching candidates still developing in the minors, not to mention the current starters who lack much of a major-league track record.

The Marlins’ best pitching prospects have reached Double-A Jacksonville this season, however, and others pitching in Advanced-A Jupiter should soon follow. With several of these talented young arms on the way up, Miami’s pitching staff will likely look a lot different by 2021.

Of course, the Marlins also need to use the final two months of this season to identify future high-leverage relievers and potential closers, particularly in the wake of their trade with the Rays that sent Nick Anderson and Trevor Richards to Tampa Bay for outfield prospect Jesus Sánchez and hard-throwing reliever Ryne Stanek.

We already looked at what the Marlins’ lineup might look like on opening day two seasons from now.

It should go without saying that this look-ahead is speculative and based on the current staff and farm system. It doesn’t account for possible trades, free-agent arms or waiver claims the Marlins can make.

So, let’s consider what an already strong Marlins pitching staff might look like in the spring of 2021.

The rotation

Sixto Sánchez (22 on Opening Day 2021): Sánchez has the arsenal to become the staff’s ace by this point with three plus pitches highlighted by an electric upper-90s fastball he throws with great movement, consistently inducing weak contact. Sánchez will likely surpass his career high for innings in a season in his next start for Double-A Jacksonville, so expect the Marlins to shut him down soon. He is the crown jewel of the club’s collection of pitching prospects, so the Marlins will continue to develop him cautiously. But a Triple-A jump by next year and an MLB debut aren’t out of the question if all goes well.

Edward Cabrera (22): It’s not far-fetched to think the Marlins could have two fire-balling, Dominican right-handers at the top of their rotation in two years. Scouts think Cabrera’s upside is close to that of Sánchez thanks to an elite fastball that has hit triple digits. Cabrera’s continued development of his slider and changeup and his command of that primary pitch will dictate how quickly he becomes a front-line starter. Cabrera, who is also in Jacksonville, could follow a similar path to Sánchez in 2020 as he tracks to a major-league debut.

Caleb Smith (29): The Marlins hung on to Smith (for now at least) at the trade deadline, instead trading Gallen for a top-100 prospect. While it’s possible the Marlins could look to move him before 2021, they could benefit from having a capable front-end lefty to complement upcoming prospects like Sánchez and Cabrera. Smith’s mix of four-seamer, slider and changeup continues to produce high strikeouts (11.04 per nine innings). His 31.2 strikeout percentage ranks fourth among NL starters with at least 90 innings pitched.

Braxton Garrett (23): Garrett has made a strong comeback from Tommy John surgery with a 2.89 ERA, 103 strikeouts and 33 walks in 90 1/3 innings with Advanced-A Jupiter this year. The Marlins won’t rush Garrett’s development, but if the lefty impresses in Double A and remains durable, he projects as a capable middle-of-the-rotation starter thanks to his curveball-changeup mix and a solid 92-94 mph fastball. Next season figures to be a year of progression for Garrett that could set up a 2021 debut if all goes well.

Fifth spot in flux

Trevor Rogers (23): This is a difficult pick since several factors over the next year and a half could influence who is in this spot. Rogers hasn’t played a full pro season until this year which could mean he needs more development time.

The Marlins’ first-round pick in 2017, however, is on a similar timeline and is producing similar results to Garrett this year in Jupiter. Rogers, another left-hander, can power his fastball into the mid-90s at times but needs to continue to work on the command of his changeup and slurve if he wants to succeed as a starter.

Trevor Rogers points to his name on the draft board after being selected 13th overall by the Marlins in 2017. (AP Photo / Julio Cortez)

That said, if Sandy Alcántara (25) becomes the consistent starter the Marlins hope he will be, maybe he sticks. Alcántara has the mix of stuff and velocity to be a front-line starter. But his lack of command at times is alarming and frustrating. Alcántara has issued an NL-worst 60 walks over his 123 innings this year, an issue that limits his options going forward. For example, would you want a guy who struggles with control as a late-inning reliever or closer? No thanks.

Jordan Yamamoto (24) had a positive outing Thursday after two consecutive rough starts, but it’s still too early to tell if he will stick in the rotation. Pablo López (25) is the other likely candidate, but health is a concern following Tommy John and some issues with his right shoulder. Both could also become controllable assets the Marlins could offer in trades between now and then as they did with Gallen. Nick Neidert (24) has lost virtually the entire 2019 season to a knee injury but could reach the majors with a strong 2020 campaign.

Bullpen

Set-up man, Elieser Hernández (25): Since predicting bullpen setups even from season to season is a fairly futile exercise, here’s a wild idea if Hernández doesn’t remain a starter. Hernández has two effective secondary pitches to complement his 91-mph fastball: a changeup and his slider, which sometimes resembles a cutter, gets a lot of swings and misses and has held batters to a .141 average this year. Hernández would enter arbitration for the first time in 2021. The Marlins could look to trade him in the coming year, too. Other intriguing set-up options by then could include recently acquired Ryne Stanek and rookie José Quijada.

Closer, Drew Steckenrider (30): The Marlins aren’t set on a closer for the final two months of this season, making the 2021 option even harder to predict. Steckenrider is the only viable remaining closing option from the three the club entered the season with, assuming he returns healthy from a forearm flexor strain. Steckenrider gave up six home runs in just 14 1/3 innings in April but was holding batters to an .071 average on his curveball. A healthy Steckenrider with restored arm strength could see more effectiveness on his fastball in 2020 and going forward. Steckenrider would enter arbitration for the first time in 2021 but could give the Marlins at least a couple of seasons as an effective closer before they weigh their long-term options.

With more payroll off the books by 2021 (including Wei-Yin Chen’s remaining $22 million), the Marlins could opt to spend big on an available free agent closer by then — a group that could include Shane Greene and Brad Hand should their respective clubs not extend their contracts. Grooming an in-house candidate before then would seem a more likely option.

(Top photo of Sixto Sanchez: Alex Trautwig / MLB Photos via Getty Images)