The Boston Red Sox had an outstanding offseason, but Craig Breslow did not bat 1.000 over the winter. The additions of Alex Bregman, Garrett Crochet and Aroldis Chapman are a massive reason why the Red Sox are currently in a postseason spot. The Walker Buehler signing, though, was nothing short of an unmitigated disaster. The Red Sox admitted this by releasing the veteran right-hander on Friday.
Red Sox have released Walker Buehler, sources say.
— Chris Cotillo (@ChrisCotillo) August 29, 2025
It was easy to see this coming. Buehler struggled so mightily in the rotation to the point where the Red Sox moved him to a bullpen role recently. With top prospect Payton Tolle set to make his MLB debut, though, Boston decided after just one (lackluster) appearance in the 'pen that they didn't have room for Buehler and parted ways with him.
By releasing Buehler, the Red Sox have all but admitted that this signing was one of the worst of the offseason. With that being said, here's where it places in a ranking among the worst signings of the winter.
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Ranking the worst mistakes of the MLB offseason after the Walker Buehler release
The San Francisco Giants signed Willy Adames to a seven-year, $186 million deal expecting to have finally signed a star. Unfortunately, he hasn't played like a star for much of this season.
The 29-year-old is slashing .224/.313/.415 with 24 home runs and 69 RBI in 132 games played. Yes, he's been much better lately, and he's still playing above-average defense, but it's hard to get overly excited about a guy making over $30 million annually having an OPS+ just nine points above the league average (109). Sure, it was reasonable to expect offensive decline to an extent given he has to play half the time at pitcher-friendly Oracle Park, but his OPS has dipped by nearly 70 points from where it was last season.
Adames showing signs of life offensively lately is certainly encouraging, but overall, there has to be some sense of regret from the Giants considering where his overall production is (and how his defense is likely to decline as he gets into his 30s).
Corbin Burnes signed a six-year, $210 million deal with the Arizona Diamondbacks, hoping to form a dominant 1-2 punch alongside Zac Gallen paired with one of the league's best offenses. Unfortunately, Burnes made a total of 11 starts before undergoing Tommy John surgery in June.
This not only ended Burnes' 2025 campaign prematurely, but will cost him most if not all of 2026 as well. It was a brutal blow for the Diamondbacks, one of MLB's most disappointing teams in 2025. Sure, he might revert to ace form when he comes back, but it's worth noting that while Burnes did have a 2.66 ERA this season, his FIP was at 3.93 and his walk rate was as high as it had been since 2020.
Burnes was already not pitching quite as well as his ERA would indicate, and now he'll be 31 years old at the earliest when he returns with a lot of money remaining on his deal. I wouldn't feel great about that deal in hindsight if I were running the Diamondbacks, although I do think Burnes can still be a really good pitcher when he does return, allowing him to rank sixth on this list.
The Toronto Blue Jays having the best record in the American League is impressive, and them being as good as they have been with Anthony Santander being a non-factor is even more so. While the Jays are in a great spot, this doesn't mean that the Santander signing was a good one in hindsight. If anything, how well they've played without him shows that they could've been even better off if that money was spent more wisely.
In the 50 games Santander has appeared in after signing a five-year, $92.5 million deal with Toronto this past winter, he's slashed .179/.273/.304 with six home runs and 18 RBI. He's been worth -0.9 fWAR this season, putting him in uncomfortable company among players with at least 200 plate appearances.
Player | 2025 fWAR (Rank) |
|---|---|
Anthony Santander | -0.9 (T-305th) |
Alex Verdugo | -0.9 (T-305th) |
Kyle Farmer | -1.0 (307th) |
Michael Massey | -1.1 (308th) |
Keibert Ruiz | -1.2 (309th) |
Josh Rojas | -1.3 (310th) |
LaMonte Wade Jr. | -1.5 (311th) |
Michael Toglia | -2.0 (312th) |
Santander has been among the 10 least valuable players in the sport when looking at fWAR among those with at least 200 plate appearances. He's been sidelined since late May with a shoulder injury, and there's no telling as to when he might return to action. He has plenty of time to turn it around, but for now, it isn't looking good.
The Buehler signing came with some risk. He came to Boston with clear durability concerns, and while the postseason track record speaks for itself, he hadn't been any good in the regular season since 2022. Signing him to a one-year deal took away some of the risk, but there was still a chance this would backfire.
Buehler wound up with a 5.45 ERA in 23 appearances (22 starts), posting a career-low strikeout rate (16.5 percent) and the highest walk rate of his career in a season in which he's thrown more than 10 innings (10.8 percent). He had a couple of good outings, but for the most part, he was hit awfully hard.
Pitcher | 2025 fWAR (Rank) |
|---|---|
Jake Irvin | -0.1 (T-95th) |
Erick Fedde | -0.1 (T-95th) |
Andrew Heaney | -0.2 (97th) |
Jack Kochanowicz | -0.6 (98th) |
Walker Buehler | -0.7 (99th) |
99 pitchers have thrown at least 110 innings this season, and Buehler ranks dead last among those in fWAR. The Red Sox have been fine in spite of him (thanks largely to guys like Lucas Giolito and Brayan Bello), but for the $21.05 million that he wound up getting, the Red Sox could've gotten much better production elsewhere. This is a deal they certainly regret doing in hindsight, but it still isn't quite the worst on the list because it was only a one-year contract. Admitting defeat with a guy who signed a short-term deal is not nearly as difficult as doing so with a player on a long-term deal.
There were few signings I liked more than the Texas Rangers landing Joc Pederson on a two-year, $37 million deal. Pederson might only be a DH at this stage of his career, and a platoon DH at that, but he was so good against right-handed pitching to the point where I thought that inserting him to an already talented (on paper) lineup would lead to great things for Texas. I couldn't have been more wrong.
The Rangers have had a very underwhelming season, and Pederson has played a huge part in that. He's slashing .171/.283/.326 with seven home runs and 18 RBI in 72 games overall, proving to be one of the biggest busts of the winter. He began his season going just 4-for-61 at the dish, and while things have been better for him lately (his current OPS of .609 is as high as it's been all season), his season has been an utter disaster.
Pederson has probably performed worse than Buehler has, and he still has an extra year on his deal. The Buehler deal was bad, but this one is worse.
Many were not high on the New York Mets giving Frankie Montas a two-year deal worth $34 million over the offseason, but considering how well David Stearns did with starting pitching reclamation projects the offseason prior, Mets fans were willing to give this one a chance. Unfortunately, their patience quickly waned, as Montas missed the first three months of the season due to injury and never looked comfortable once he returned.
Montas posted a 6.28 ERA in nine appearances (seven starts) and things were only getting worse the more he pitched. Eventually, it was revealed that Montas has a UCL tear in his elbow, and will miss not only the remainder of the 2025 campaign but possibly all of 2026 as well.
The Mets gave Montas a fairly expensive two-year deal to make a total of nine appearances, five or six of which were brutal. He likely won't throw another pitch in a Mets uniform. Even without the injury, he would've been a potential DFA candidate over the offseason. The injury all but seals his fate in Queens, and makes this one of the worst signings of the winter. What I will say, though, is at least he pitched.
The Detroit Tigers giving 37-year-old Alex Cobb a one-year, $15 million deal felt awfully questionable following a season in which he made just five starts between the regular season and postseason, especially when taking his lengthy injury history into account. Even Cobb admitted he thought about retirement before the Tigers and some other teams expressed interest in signing him.
The deal has aged worse than Tigers fans could've expected. Cobb suffered a hip injury before spring training and has been dealing with issues in both of his hips all season long. He's been able to make nine starts across a couple of different rehab stints, but he was just pulled off his recent rehab assignment with hip soreness.
Sure, Cobb can come back at some point either in the regular season or in October, but should Tigers fans really expect that to happen at this point? It's late August, Cobb hasn't thrown a single pitch for the Tigers and he was just put back on the shelf. Obviously, the Tigers didn't expect the deal to age this poorly, but hindsight is 20/20. Giving Cobb $15 million to likely not throw a single pitch for the team this season is not the best use of money.