2023 In Review: An Up-And-Down Season for Garrett Whitlock

Boston Red Sox v Washington Nationals
Photo by Mitchell Layton/Getty Images

Elbow issues resurfaced this year, leading to multiple stints on the IL and a return to the bullpen in the second half of the season.

2023 In One Sentence

Looking to establish himself as a perennial member of the rotation, Whitlock once again encountered elbow issues requiring multiple IL stints and contributing to a choppy season performance-wise.

The Positives

It may seem like a lifetime ago, but Garrett Whitlock began the 2023 season in the starting rotation and made ten starts, totaling 51 2/3 innings, between April 11th and July 2nd. There was a five-week hiatus in that time, wherein Whitlock was diagnosed with ulnar neuritis of the elbow, which sidelined him a second time when he left the July 2nd start against Toronto with further elbow pain.

In his first eight starts, Whitlock pitched into the seventh inning four times. He was efficient in all of these outings, with pitch counts of 99, 92, 88, and 92, and completed a full seven innings three times, looking like the peak Garrett Whitlock that we had seen on so many occasions during the 2021 and 2022 seasons.

Even in a down year, Whitlock’s ground ball rate ticked back up from 40.8% in 2022 to 44% in 2023. Unfortunately, a ground ball pitcher wasn’t the best fit for the 2023 Red Sox and their defense, and Whitlock’s BABIP was .340. His walk rate was elite, walking just 4.3% of the batters he faced, which kept him in the 98th percentile in the entire league. He also was in the top-15 percentile of pitchers in Chase % (32.3). Whitlock’s baseline of keeping the ball down, maintaining elite control, and getting batters to chase out of the zone were all still there. Unfortunately, when the pitches in the zone got hit…

The Negatives

… they got hit hard. Whether it was Barrels, Hard Hit percentage, or Exit Velocity, Whitlock has gone from extreme red to extreme blue in a matter of two years.


Baseball Savant

Whitlock’s HR/9 in his three seasons has gone from 0.74 to 1.15 to 1.63. In 2023, that was a result of a decline in the changeup over anything else. He left the pitch out over the plate far too often and saw the pitch get hit hard all year long.


Baseball Savant

Whitlock also continued to have issues staying on the field. After his 2022 season was cut short by a hip injury, which required surgery, he ramped up slowly in spring training and didn’t take the mound until the eleventh game of the season. The neuritis of the elbow reportedly did not lead to any nerve damage, but we’re talking about a pitcher who already had Tommy John surgery in 2019 having elbow issues again. Fortunately, at least this year, Whitlock was on the mound when the season ended, even getting his lone save of the year in the final series of the season against the Baltimore Orioles.

Best Game of 2023

In his first career start at Yankee Stadium on June 9th, the former Yankee prospect strikes out six in 6 13 innings, allowing one earned run. All six strikeouts come on sliders and changeups.

The Big Question

Can Garrett Whitlock regain command of the changeup and make the case to continue being a starting pitcher for the Red Sox? To be a starter, Whitlock needs to have three pitches in his arsenal that he can rely on. As mentioned earlier, the changeup allowed a .312 BA and .559 SLG% in 2023. Whitlock’s best outings last season as a starter were directly correlated with his best outputs from the changeup.






Baseball Savant

When tuning into a Whitlock start, you can usually tell pretty early whether he has the changeup working. When he does, the batters are off balance, the pitch counts stay in check, and the bullpen can be saved. Depending on how Craig Breslow assembles his rotation with upcoming offseason moves, Whitlock could be battling for the fifth starter position or pitching as a high-leverage reliever. For many, the stats so far tell the story:

Starter (career): 19 G, 90.2 IP, 5-4, 4.76 ERA, 1.29 WHIP, .282/.316/.475/.791

Reliever (career): 80 G, 132.2 IP, 12-7, 2.65 ERA, 1.05 WHIP, .222/.269/.364/.632

One metric that Whitlock sits at the top of the league in is “Extension” (check out the extension on that cover photo!) With Breslow bringing in other pitchers (Cooper Criswell, Justin Slaten) who are tall and get great extension, you have to wonder if he looks at the 6’5” Whitlock with the 100th percentile extension and thinks there is more upside there. I’m in the minority in that I believe he still has the profile of a starter, but a fully healthy season would go a long way in proving that to be true for Garrett Whitlock.

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