How do Mark Vientos and Kodai Senga fit into the Mets run prevention plan?
Both Vientos and Senga epitomized the Mets primary issues for most of the 2025 season
What’s up with the Mets? ⚾️
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The Mets Kodai Senga and Mark Vientos problem ✍️
The Mets have a few problems on their roster that they need to decide on going forward, don’t they?
Two of those problems epitomized their problems in 2025 specifically, and they were Kodai Senga and Mark Vientos.
Both players represented the club’s primary issues, which led to their demise this season, specifically around pitching, defense, and run prevention (the latter of which, of course, combines their issues with pitching and defense).
Today, I’ll discuss both of those players in two separate parts and how the Mets could conceivably proceed with both, or not.
MARK VIENTOS
Suffice it to say, Vientos was dreadful for the bulk of the 2025 season after what could only be described as a brilliant 2024 season. Sure, there were flashes, and his second half was quite a bit better than his first half, but generally speaking, Vientos was a net negative for the Mets and was relegated to right-handed DH work by the end of the season. They were reportedly looking for a trade partner for Vientos ahead of the trade deadline. He missed three weeks with a mild hamstring strain in June, but was probably punching a ticket to the bench anyway at that time, no matter what.
So, what happened to Vientos?
Well, nothing happened to his defense. He was a problem at third base in 2024 to the point that the Mets were pondering moving him to first in the event Pete Alonso walked last winter (which was a terrible idea, but whatever). His defense was quite a bit worse in 2025 than it was the year before, but that wasn’t necessarily a surprise given his skill set. He had -10 defensive runs saved (DRS) at third this year, -7 outs above average (OAA).
The problem was his offense (although, make no mistake, his defense was brutal, but he’s a bat-first player and we knew that coming in), which was generally absent until mid-July. He did hit reasonably well from July 10 on, posting a .257/.307/.486 slash line with 13 doubles, 1 triple, 11 home runs, and 40 RBI over 228 plate appearances during that span, but it’s not as if that is an off-the-charts trajectory over a 162-game pace. He had a sub-.400 slugging percentage against right-handed pitchers this season, had a sub-.300 on-base percentage overall, was way too swing-and-miss, and chased way too much, specifically movement pitches which he never was able to handle over the course of the year. He had a -6 run value against sinkers and had a .298 slugging percentage against that pitch, a -1 run value against sliders, and hit .197 against those, and a -5 run value against sweepers and hit .196 with a .196(!!!) slugging percentage against those.
Combining his defense and offense, Vientos was generally unplayable this year, which is both surprising and unfortunate considering how much he meant to the 2024 team and their deep run into October. His absent offense resulted in the Mets being too top-heavy in their lineup, his absent defense made him a liability at third, and that resulted in borderline replacement-level play throughout the year. If not for being out of options, Vientos might have found himself at Triple-A.
So, where do the Mets go from here?
Vientos isn’t a big earner here. His $788,000 salary is inconsequential to the payroll, and he isn’t arbitration-eligible for another season, assuming he amasses the requisite amount of playing time over the next year. But with the Mets’ primary objective of improving their defense, it’s really hard to see how Vientos fits into that equation given his skills defensively. That’s not to say they can’t make him a bat-first player on this roster and relegate him to DH duty, but the problem with that is the larger sample size suggests he’s best suited as a part-time bat against left-handed pitching.
And quite frankly, I don’t think the Mets should afford a part-time role to a bat-first player, especially when they’re trying to improve defensively. Rather, part-time roles should be assigned to versatile players, arguably defense-first players.
It might not have been so easy to come to this conclusion with Vientos had Brett Baty not taken over third base the way he did this season. And I would certainly argue that part of Vientos’ problem this year might have been that cold bucket of water hanging over his head with each play and each at-bat, given he was competing daily with Baty and Ronny Mauricio.
But in the end, his numbers are what they are, and he profiles the way he profiles. That isn’t providing much value to the Mets right now or in their future plans.
KODAI SENGA
Where do I begin with Senga? What a mess this situation has been for the last two years.
The Mets built a rotation plan and, quite frankly, their entire infrastructure, around Senga this past season. They wanted to ensure he was only going to pitch once per week, they catered to every need he had in order to make him feel more comfortable and to maximize his performance, so they manicured their entire rotation strategy around the one player.
And as we know, whenever a team in sports makes it about one player, things don’t usually go so well.
Now, they did for the first 2 1/2 months of the year, although Senga wasn’t throwing that many innings because he was only pitching once per week. He had a 1.47 ERA through June 12, which spanned 13 starts and 73.2 IP, an average of 5 2/3 IP per start. That’s pretty good considering the Mets tend to slowly ramp their pitchers up over the course of the season, yet they had Senga pitch into the sixth inning or later ten times over those first 13 starts.
But of course, June 12 is the line of demarcation for the 2025 Mets, and the date everything began to go south.
It started with Senga hurting his hamstring on what was a routine play at first in which he had to cover on a throw from Pete Alonso. But Alonso’s throw was high, Senga had to overreach, and he strained his hamstring, costing him three weeks and sending the whole pitching staff into chaos from there.
But when Senga returned, he just wasn’t right. He wasn’t pitching well, he wasn’t going deep into games, and ultimately, he was asked to go to the minor leagues, from which he never returned this year.
He cited mechanical problems as the root cause of his struggles, but he was unable to find a routine which would help him restore the mechanics he claimed he lost. So, a once promising season for Senga following a lost season in 2024 turned into another lost season in 2025, and uncertainty about his future in the major leagues.
It was David Stearns who said two weeks ago it would be “foolish” to pencil Senga in for 30 starts next season. So, that pretty much tells the story of what they think of Senga at this point after year three of the five-year contract he signed with the Mets.
The truth is, the Mets have gotten one year of production out of Senga all while trying to maintain him and cater to his needs. Needless to say, the juice hasn’t been worth the squeeze to this point, and they haven’t gotten enough from him over the last three years with respect to the amount of money and effort they have invested.
Look - he was great in his rookie year in 2023, to the point he was an All-Star, seventh in Cy Young voting, and second in rookie of the year voting. But that was two years ago, and he has made 23 starts since. Last year was a mess between his shoulder and the calf and the ridiculous rostering in the playoffs, and while this year got off to a promising start, he lost his way in the end, and the club can only look at the bulk of the body of work to draw their conclusion.
I don’t know if the Mets will look to move him, I don’t know if the Mets will look to transition him to the bullpen, or what. But what we do know is if the Mets can’t expect Senga to make 30 starts, the Mets can’t realistically expect him to be a meaningful part of their rotation plan going into 2026. And at $14 million for next season, that’s an albatross and fat that needs to be trimmed from the roster, if that is the case.
If the Mets move forward with Senga, they can’t view him as anything other than a back-of-the-rotation arm, and they certainly can’t design a rotation strategy around him anymore.
So, I can only conclude the Mets will look to find a taker for Senga and the remaining two years and $28 million he is guaranteed over the next two seasons. That could prove difficult for the Mets, but getting that roster flexibility back at this point might have more value than the return he might provide or having to structure a pitching staff around him.
It’s funny though - coming into 2025 Senga was looked at as a top-of-the-rotation arm, and he pitched like that through the season’s first 70 games.
Now, we are talking about him maybe being elsewhere. Funny how things change on a dime in this game.
But if the Mets intend to get better on the mound, they’re going to have to make some wholesale changes, even if it is a tough chore like this is.
Vientos's future as a Met is largely dependent on what they do with Alonso. If they resign Pete, they'll trade Vientos. If not, he'll have a chance to redeem himself as a first baseman/DH. As for explaining his dismal 2025 season, my assertion was that he had let success go to his head. During the winter, he was seen celebrating at MSG, sporting frosted tips and bling, more befitting of his alter ego, "Swaggy V", and I immediately thought he had become a little full of himself. He followed that by cruising through spring training as the incumbent third baseman and wasn't really ready to go, from a mental standpoint, when the bell rang. As the season went on, frustration set in and he dug himself deeper and deeper into a lost season. My hope is that this experience humbled him and he'll work hard to regain his status and the trust of the organization.
As far as Senga is concerned, I think the problem is in the six inches between his ears! I can't recall another Japanese pitcher who has been as coddled as Senga, during his time with the Mets. I think they should cut bait and trade him to the Dodgers. They can afford to allow him to spend half of the season on Injured List.
Senga might have been the best pitcher in the NL before he got hurt. His injuries and lack of availability every 5th day is the issue. If I were Stearns I’d consider moving anyone but the young arms if the deal made sense.