Sep 21, 2025; New York City, New York, USA; New York Mets third baseman Mark Vientos (27) reacts after striking out against the Washington Nationals during the fourth inning at Citi Field. Mandatory Credit: John Jones-Imagn Images John Jones-Imagn Images

Mark Vientos may be Mets' toughest offseason question

Originally posted on New York Mets on SI
By Andrew Jamieson | Last updated Oct 9, 2025 4:00 PM ET

The New York Mets have a number of offseason questions to address, including what to do with free agents Pete Alonso and Edwin Díaz. But there may be no bigger question than the decision surrounding Mark Vientos.

Heading into 2025, the 25-year-old third baseman was viewed as a potential core piece for the Mets after a breakout 2024 campaign in both the regular season and playoffs. However, Vientos took a clear step back this season.

After slashing .266/.322/.516 with 27 home runs and 71 RBIs in 2024, he followed up with a disappointing .233/.289/.414 line in 2025, totaling just 17 home runs and 61 RBIs. Though he had flashes of his 2024 self, there was never consistency.

Furthermore, his defensive struggles, highlighted by a -7 outs above average in 2025, only added to his struggles at the plate and contributed to reduced playing time as Brett Baty emerged.

David Stearns on Run Prevention

In his end-of-season press conference on September 29, president of baseball operations David Stearns emphasized run prevention as a key reason why the Mets fell short of expectations in 2025.

"Our defense wasn't good enough, and that certainly contributed to our pitching challenges," Stearns stated. "Clearly, that was a point in our season where on the run-prevention side of things we went from a very good team to a team that wasn't good enough to maintain a sizable lead -- not only in the division, but in the playoff chase."

David Stearns was asked what the most "fixable" thing is for the Mets moving forward:

"I'll keep harping on run prevention. That is where we feel short this year." pic.twitter.com/ZlcSBmbgKl
— SNY (@SNYtv) September 29, 2025

That emphasis on defense doesn't bode well for Vientos, as both Baty (1 OOA, 70th percentile ) and Ronny Mauricio are stronger defenders and more versatile in the infield.

Still, Vientos offers real offensive upside heading into his age-26 season. The power is there, and although he struggled this past season, his hard-hit percentage (50.5), average exit velocity (91.4) and barrel percentage (11.5) are all above league average.

Mark Vientos is HOT

He's got 6 homers and 17 RBI in his last 10 games! pic.twitter.com/Vn9mgHU2Dz
— MLB (@MLB) August 28, 2025

That power could prove valuable if Alonso departs this offseason. On top of Alonso, Starling Marte and Jesse Winker are also set to be free agents, meaning the Mets won't have any clear candidates to serve as the designated hitter in their lineup.

More likely than not though, the decision on Mark Vientos will hinge on what happens with Pete Alonso. If Alonso stays, Vientos could become a trade candidate, offering the Mets a chance to find a ace to frontline their rotation. But if Alonso departs, keeping Vientos may be necessary to preserve some offensive firepower in the lineup.

This article first appeared on New York Mets on SI and was syndicated with permission.

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