Three years ago this month, the Miami Marlins traded their 26-year-old left fielder – with two years left of team control and a bat that was finally showing its potential – for four prospects, three of them pitchers.

Marcell Ozuna was shipped to St. Louis, where he put up two mediocre seasons for the Cardinals before he hit the free agent market, where he now finds himself once again.

It worked out just fine for the Marlins, who landed flamethrower Sandy Alcantara (3.71 ERA since the deal), Daniel Castana (3.03 ERA), Zac Gallen (2.78 ERA) and outfielder Magneuris Sierra (.576 OPS).

Why is this trade relevant to the Red Sox this winter?

They’ve got their own 26-year-old left fielder with two years left of team control, but a bat that hasn’t yet lived up to its potential, in Andrew Benintendi.

As the Red Sox continue to search the free agent market and consider their options via trade, Benintendi’s name sure comes up often. He’s far from an integral member of the Sox’ organization, but can be. They don’t have a lot of big league pieces that are both expendable and valuable, but Benintendi is both of those.

They don’t have a deep enough farm system to dig into. And they already have a pair of corner outfielders on their roster in Alex Verdugo and Hunter Renfroe.

Verdugo is an everyday player, not a platoon player, as he showed quite clearly in 2020. Barring an unlikely scenario in which Verdugo is the everyday center fielder, Renfroe’s platoon at-bats should be coming at the expense of Benintendi, who has a career .691 OPS against lefties and could use the respite.

The Red Sox will need another outfielder, preferably one who can play center field quite well. This position will be crowded.

So what do they do? Trade Benintendi and try to add some young pitching depth to their organization? Or hold onto the former No. 7 overall pick and hope his sweet swing from the left side is about to bust out after a lost year due to a rib cage injury?

That all depends on the return that chief baseball officer Chaim Bloom is able to fetch. It’s not a perfect time to be dealing a left-handed hitting outfielder, given there are a few good ones on the free agent market in Michael Brantley, Joc Pederson and, yes, Jackie Bradley Jr.

There is one key difference between Benintendi (career .789 OPS) and Ozuna (.786 OPS before he was traded). While Benintendi is coming off his worst career season, Ozuna was coming off a near-MVP season in 2017: .312 average, .924 OPS, 37 homers and a Gold Glove in left field.

But while Ozuna was never ranked better than a No. 75 overall prospect by Baseball America and struggled to impress during his first four big league seasons, Benintendi was once the unanimous No. 1 prospect in baseball and has 3 1/2 very good seasons on his resume already.

What Ozuna showed in results, many believe Benintendi has in potential.

It’s interesting to look back at Cardinals’ General Manager John Mozeliak’s comments about Ozuna when the team acquired him. It sounds as if he could be talking about Benintendi.

“Whenever I watched him, I was like, ‘he could be so good,'” Mozeliak said of Ozuna at the time. “I always sort of wondered why he wasn’t. What do great players do that other players don’t? When they do things, they make it look easy. He always had a quick bat, would hit the ball hard, and I always just sort of wondered why he didn’t do more.”

And here’s what Bloom said of Benintendi at the end of his injury-plagued 2020 season:

“This is a guy who has shown the ability to perform at a really high level, including in some really critical situations. Still young. Still has all that ability. It’s just a shame his year kind of got wiped out.”

Red Sox Manager Alex Cora got the best out of Benintendi in 2018, but oversaw his drop-off in ’19.

“When this kid got drafted, he was probably the best hitting prospect coming out of college,” Cora said recently. “Those first-rounders, they don’t get lucky, they’re good. I still believe Andrew Benintendi is a good player, I think Andrew Benintendi is an impactful player and we need to get him back to that mindset that he had in ’18 and even in ’17.”

At this point it’s hard to wonder if we’ve already seen exactly the player he is: a good gap-to-gap doubles hitter with a little power, a little speed and below-average defense in left field, where he was considered the worst in the American League in 2019.

The Red Sox have some young pitching about ready to make an impact in Tanner Houck, Jay Groome, Bryan Mata and Thad Ward. They could certainly use some more after they traded a pair of their best relievers in Brandon Workman and Heath Hembree in 2020.

Benintendi, who will make $6.6 million in 2021 before his final year of arbitration-eligibility in 2022, might be the best trade chip they have.