Magneuris Sierra: professional good-luck charm

Assuming no setbacks, Starling Marte (fractured rib) is on track to rejoin the Marlins active roster next week. During his absence, Magneuris Sierra has been Miami’s most frequently used center fielder. Any way you slice it, Sierra’s production pales in comparison to Marte’s, and his track record prior to 2021 does not inspire much confidence, either. On the surface, he looks like a candidate to be designated for assignment in the near future.

Yet remarkably, while Marte has been sidelined and especially when Sierra has started in his place, the Marlins have stayed afloat. They enter Tuesday just one game back of the National League East division lead and own the fourth-best run differential among all NL teams.

The phenomenon dates back to the 2020 season—since then, the Marlins are 17-9 when Magneuris Sierra is in their starting lineup. That’s a .654 winning percentage, which is the highest of any Miami position player over that span (minimum five games started). The next-highest belongs to now-retired catcher Francisco Cervelli (.625).

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With Mags in the lineup, the Marlins play like the world champion Dodgers. Without him, they are mediocre (.457 winning percentage).

Sierra is often clumped together with Lewis Brinson as an athletic mid-20s outfielder who never quite delivered on his early-career prospect pedigree. The Marlins are only 18-24 (.429 W-L%) since 2020 when Brinson starts. Any rational person would agree that Jazz Chisholm Jr. is a superior player to Sierra, yet his correlation with the team’s success is not nearly as strong (22-23, .480 W-L% in Chisholm’s starts).

When used as a starter the last two seasons, Sierra has slashed .250/.333/.333 with 4 SB and a 19.4 K% in 98 PA. That’s passable for somebody at the bottom of the order, but doesn’t move the needle. A few of his aggressive baserunning decisions from 2020 helped to spark Miami rallies, for what it’s worth. He has been a very good fielder for the Fish, totaling 7 Defensive Runs Saved and 4 Outs Above Average (though some of that was accumulated in appearances off the bench). It’s not as if he single-handedly transforms the club’s run prevention—the Marlins are actually allowing more runs per game in his starts (4.88) than his non-starts (4.36).

I’m not finding anything as an analyst or a viewer that supports the idea of Sierra as a true x-factor. Based on Don Mattingly’s handling of him earlier this season—zero starts prior to Marte’s injury—the Marlins seem to be in the same camp.

There is a possibility of Sierra being DFA’d in June to accommodate the returns of Marte and Elieser Hernandez (who needs a 40-man spot) and the potent bat of prospect Jesús Sánchez. Every roster spot is vital for the Marlins if they are committed to continue boosting their still-slim playoff odds.

However, if/when that day comes, Sierra should be appreciated for the subtle ways in which he has impacted winning. The Marlins’ brass will have their fingers crossed that a sub-replacement career WAR total and being out of minor league options enables him to clear waivers and continue his career in their organization.