Should the Red Sox use a 6-man rotation in 2023?

The Boston Red Sox made only one external addition to the starting rotation this off-season. The team signed veteran right-hander Corey Kluber to a 1-year, $10 million deal (which included a 2nd year club option).

The team's lack of starting pitching depth during the 2022 season was a major weakness, but all internal candidates for the rotation in 2023 seem to be getting healthy at just the right time. If this trend continues, it may pose a challenge the standard convention of a 5-man rotation.

Should the Red Sox consider using a 6-man starting rotation in 2023?

In all, 12 pitchers made starts for the Red Sox in 2022. Nick Pivetta, Rich Hill, Michael Wacha, and Nate Eovaldi ranked 1st through 4th (respectively) in most starts made, but the team also needed Josh Winckowski (5.89 ERA), Kutter Crawford (5.47 ERA), and Connor Seabold (11.29 ERA) to make a combined 31 starts.

With Rich Hill and Nate Eovaldi signing elsewhere during this off-season, and with Michael Wacha remaining a free agent at the time of this article, 3 pitchers that combined for 69 starts (361 IP) in 2022 need to be replaced. Corey Kluber is expected to replace some of the production that was lost over the off-season, but several others will likely play a larger role in 2023, as well.

Garrett Whitlock and Brayan Bello made 20 combined starts last season, but it is possible that both make the Opening Day roster as starting pitchers. Chris Sale, the team's ace, is also on-track to be ready for Opening Day. Another lefty, veteran James Paxton, exercised his 1-year, $4 million player option this off-season to return to the Red Sox for another year. Paxton has been a starter his entire career.

This means there are 7 legitimate contenders for the starting rotation currently on the roster: Chris Sale, James Paxton, Corey Kluber, Nick Pivetta, Garrett Whitlock, Brayan Bello, and Tanner Houck. Kutter Crawford and Josh Winckowski, who ranked 5th and 6th on the team in starts made last season, also remain on the 40-man roster for the Red Sox.

With additional options like Bryan Mata, Chris Murphy, and Brandon Walter also available to make a spot start mid-season in 2023, it is safe to say that the Red Sox have no shortage of starting pitching. However, will they break away from the standard convention of a 5-man starting rotation?

Red Sox representatives have stated that, up to this point, the idea of a 6-man rotation has not been considered. Going this route can be beneficial to the starters, giving them an extra day's rest between outings, but it can quickly take a toll on the bullpen. There are a finite number of roster spots available to the team during the regular season and having 6 starting pitchers will mean that the club will likely carry one fewer reliever (unless they opt to instead carry one fewer position player).

Former Red Sox 3rd baseman (and now NESN analyst) Will Middlebrooks offered a similar sentiment on bullpen burnout from a 6-man rotation, and expanded further to provide a potential alternative solution to the 2023 rotation via a Twitter post on Saturday night:

As Middlebrooks stated in his post, "easing your starters into the season" is definitely an attractive element of a 6-man rotation. It would also allow for proper load management as the season draws onward, and that may be critical for the personnel comprising this particular rotation.

Chris Sale hasn't made more than 27 starts in a single season since 2017. His maximum innings pitched since that time was in 2018 (158 IP). James Paxton has never made more than 29 starts in his entire career. Garrett Whitlock and Tanner Houck have never spent a full season at the major league level as full-time starting pitchers. Brayan Bello has never pitched more than 153.1 innings during any single season in his professional career. He set that mark in 2022.

In addition to entering unchartered territory in terms of single-season workload for many of these pitchers, reducing injury risk also needs to be front-of-mind. Sale, Paxton, and Kluber are each only 2-3 years removed from having Tommy John Surgery, and Kluber is the only one of the trio who has returned to a full-season workload after recovery (making 31 starts in 2021 with the Tampa Bay Rays). The Red Sox may consider putting restrictions on either pitch count or innings pitched (or both) for these starters in 2023.

If all 6 pitchers in a hypothetical 6-man rotation remained healthy for a full 162-game slate, each would make 27 starts and log 162 innings (assuming 6 innings pitched per start). This would roughly align with Sale's 5-year high, Bello's and Paxton's career highs, and Kluber's 2022 workload.

A Red Sox 6-man rotation going into 2023 could consist of Chris Sale, Corey Kluber, James Paxton, Garrett Whitlock, Nick Pivetta, and Brayan Bello, with Tanner Houck being a multi-inning reliever who could be used in high-leverage spots to record 6 to 9 outs per outing roughly twice per week.

Using 6 starting pitchers would mean that the team only carries 7 relievers (assuming 13 pitchers and 13 position players on the 26-man roster). This creates a situation where the team addresses one issue (reducing wear-and-tear and injury risk for the rotation) while creating another (increasing wear-and-tear on the bullpen).

Between the public messaging from the team and the risk of wearing down the bullpen, I don't think a 6-man rotation is realistic to expect at this point. I do, however, think that multiple starting candidates (James Paxton and Tanner Houck) will be added to the bullpen in bulk-inning roles. This may change as spring training progresses, since it remains possible that not all starters will be healthy by Opening Day.

If the season began tomorrow, these would be my predictions for the Red Sox starting pitchers and relief pitchers on the Opening Day roster.

Starters: Chris Sale, Corey Kluber, Garrett Whitlock, Brayan Bello, Nick Pivetta

Relievers: Tanner Houck, James Paxton, Kenley Jansen, Chris Martin, John Schreiber, Joely Rodriguez, Richard Bleier, Ryan Brasier

Other bullpen candidates going into spring camp include Zack Kelly, Kaleb Ort, Wyatt Mills, Ryan Sherriff, and Kutter Crawford. Zack Kelly is likely the highest ceiling option of the group, and strictly on the basis of merit should be on the Opening Day roster. However, his 3 options remaining offer tremendous roster flexibility for the Red Sox.

In contrast, Ryan Brasier has a veteran classification so he comes with no options; the other "on the bubble" candidates previously listed each have fewer than 3 options remaining. While Kutter Crawford was effective at times with the Red Sox last season, he is more than likely to start the year with the WooSox as a starting pitcher in their rotation. This allows him to serve as a form of insurance - along with Josh Winckowski, Bryan Mata, and others - in case the Red Sox need a spot start.

In closing, I don't believe the Red Sox will seriously entertain utilizing a 6-man rotation to start the season. Instead, the team may add Tanner Houck and James Paxton to the bullpen as long relief options, which will help reduce the workload of the starters while also saving the bullpen from burnout.

It will be interesting to see how spring training unfolds, with a lot of competition expected for a few spots in the rotation and bullpen. Regardless, cheers to good health and good baseball! The 2023 season is just around the corner!