The Mets’ rotation is old, and everybody knows it. Their staff is a good one, but it’s certainly mature: when the season starts, four Mets starters (Carlos Carrasco, Justin Verlander, Max Scherzer, and José Quintana) will have a combined age of 148. Kodai Senga seems young because he’s new, but he’s already 30. If you’ve been around the Mets longer than five minutes, you’ve heard the jokes: “The Mets are running a nursing home! These guys are going to have to take off their sweater-vests to pitch! Training staff had better stock up on Bengay!”
The staff, to use a popular phrase, is a mile wide and an inch deep. It’s a house of cards. The top five starters are excellent, but the second a few injuries hit, you’ve got José Butto starting every fifth day. Which is why the Mets should take a long, hard look at starting the season in a six-man rotation.
As things stand right now, Carrasco is probably the Mets’ fifth starter. The actual order of the rotation doesn’t really matter; that’s more to say that Carrasco is the Mets’ fifth-best starter. He’s the margin at which a sixth starter can improve or detract. The Mets’ sixth-best starter, meanwhile, is David Peterson, who might be every bit as good as Carrasco in 2023.
Peterson pitched to a 3.83 ERA in 28 games (19 starts) in 2022. He’s certainly not an ace; he does some things well and some things badly. He gives up a lot of hard contact; he strikes out a lot of hitters. He throws a tiny bit harder than average, and his xBA and xSLG are good; his xERA in 2022 was slightly below average, and he walks a lot of hitters. He’s no fireballer, but he’s a fine fifth — or sixth — starter.
The real point of a six-man rotation, though, isn’t to get Peterson more starts. If the Mets’ top five starters were all ten years younger, then Peterson would fit perfectly in the bullpen. But heading into 2023, the rotation could use some careful handling, and Peterson is the one who can provide it.
In his career, Justin Verlander has pitched to a 3.08 ERA on four days rest, a 3.49 ERA on five days rest, and a 2.89 ERA on six days rest or more. For Max Scherzer, the numbers are 3.18, 3.04, and 3.01. Quintana follows the same pattern: he’s pitched to a 3.94 ERA on four days rest, 3.69 on five, and 3.31 on six-plus. Carrasco has actually been better on five days rest than six, but he’s clearly the exception. He’ll also be 36 on Opening Day, so regardless of career stats, the more rest, the better.
Those numbers aren’t even the most important part. It doesn’t really matter that most of the Mets’ older starters are better on six days rest than five. Even if there was no difference, or they got slightly worse on six days rest, a six man rotation would still make sense, for the simple reason that having an excellent starter pitch an entire season is — obviously — much better than having that same starter pitch slightly more often, but not make it through the season healthy.
Verlander missed time last September with a right calf injury. Scherzer had oblique trouble all year. Carrasco also dealt with an oblique strain, and was injured for most of 2021. Quintana was healthy in 2022, but missed time with shoulder inflammation in 2021. This isn’t breaking news to anyone: pitchers, particularly older pitchers, tend to get injured. Which, for the 2023 Mets, would be bad.
A six-man rotation isn’t a foolproof defense against injury, but it’s something. And regardless of how good Peterson is, his real value in such a rotation isn’t his pitching itself: it’s his contribution to keeping the rest of the staff healthy. Which is better: Peterson pitching every sixth day, and Verlander and Scherzer making 28 starts each? Or Peterson pitching out of the bullpen, and Verlander and Scherzer getting worn down pitching every fifth day and missing a month each with injuries?
Starting the season in a six-man rotation doesn’t mean the Mets have to stay in a six-man rotation. If Peterson falls apart the way he did in 2021, he can go back to the bullpen, and the Mets can revert to a traditional pitching staff and pray for healthy arms. But if Peterson can keep pitching like he did in 2022, or anywhere near that level, he belongs in the rotation. Indeed, he might even have a better year than Carrasco. He’s good enough to give the Mets a chance in every game he pitches. More importantly, though, he’s good enough to give an aging staff an extra day off each time through the rotation, and help keep Mets pitching healthy deep into October.