One of the worst trades in Miami Marlins history took place on January 25, 2018. That was the horrible trade when The Fish sent LF Christian Yelich to the Milwaukee Brewers for top prospect OF Lewis Brinson, and prospects 2B Isan Diaz and OF Monte Harrison. This trade was a disaster and it gets worse when you look at who potentially could've been available instead. It's another in a sadly line of mistakes by the team.
The Miami Marlins could've made a franchise-altering trade.
None of the three prospects acquired by the Miami Marlins worked out for the team. Monte Harrison was on the team from 2020 to 2021. He batted .175/.230/.263 in 41 games and 57 AB. He was a complete disaster and certainly was no asset.
Isan Diaz didn't do much better for The Fish. He batted a dreadful .185/.275/.287 in 145 games and 439 AB from 2019 to 2021. Of course all of that still pales in comparison to how Lewis Brinson did with the team. Brinson was the big star of the deal and he was in fact the headliner of the trade.
Lewis Brinson played for the team from 2018 to 2021. He batted a horrible .203/.258/.325 in 320 games and 988 AB. It was a large sample size and he was the headliner of the trade, so you can clearly see that this was a disaster of the trade.
It's important to point out that The Fish probably could not have acquired any of the two elite prospects for Christian Yelich. RF Ronald Acuna Jr. has played for the Atlanta Braves since 2018. In the 722 games and 2818 AB, he batted .289/.379/.525. The Braves did refuse to trade him, but perhaps the Marlins could've sweetened the deal. The Toronto Blue Jays were also unwilling to trade 1B Vladimir Guerrero Jr. Vlad has played for the team since 2019. He's played in 819 games and 3145 AB. He batted .288/.363/.500.
Both Atlanta and Toronto rejected trading their top prospects, but we can only imagine who the Miami Marlins could've acquired and who knows if The Fish could've done something to change their minds.