Projecting the 2021 Detroit Tigers: This starting rotation could be really, really good

With the trade deadline comfortably in the rearview mirror and the end of the season only a month away, we are beginning to gain clarity on the outlook of the Detroit Tigers’ system moving into 2020 and beyond.

We wanted to look at the Tigers long-term pitching outlook and try to predict the team’s 2021 rotation and bullpen. This rebuild is built on a foundation of pitching, not hitting, so to look at hitting first when the lineup’s reconstruction still hinges on future trades, drafts, or free agent expenditures, would be an exercise in futility (we’ll still probably try, though).

Recently, FanGraphs’ Marc Hulet suggested that the Detroit Tigers have the best pitching depth of any system in Major League Baseball.

Firstly, they have three pitchers at the top that project to develop into No. 1/2 starters. Secondly, the organization could graduate five strong starting pitchers by the end of the 2020 season. The club also projects to completely makeover the starting rotation by 2021 which could push Spencer Turnbull to the bullpen and allow the Tigers to deal Matthew Boyd for help on the hitting side.

It’s hard to not to daydream about a Casey Mize, Matt Manning, and Tarik Skubal-led top of the rotation that brings us back to the days of Justin Verlander, Max Scherzer, and 2013 American League ERA champion Anibal Sanchez baffling hitters on a nightly basis. But let’s try to keep our emotions in check.

Let’s break down what the future may actually look like for the Tigers’ rotation, and see if Hulet is on to something with pushing Turnbull to the bullpen and dealing Matthew Boyd (assuming his recent struggles do not persist and he finishes strong like he did in 2017) to another team.

Part I: Projecting the Rotation

To all the Edwin Jackson enthusiasts out there, I am sad to inform you he is likely not in the team’s long-term plans for the rotation. That said, there are three current Tigers pitchers who may have a future in this rotation: Matthew Boyd, Spencer Turnbull, and Daniel Norris.

Boyd is the most obvious candidate of the three; after all, he has the sixth-highest strikeout percentage in baseball this year at 31.2 percent. Boyd also excels at limiting walks, as his 5.7 percent walk rate is tied for 16th-best among qualified starters. Boyd’s issue is the long ball, as he allows 1.85 home runs per nine innings — fourth-highest in baseball.

And who allows the fifth-most home runs per nine innings? Daniel Norris, with 1.72 per nine. Nevertheless, Norris could be a piece in the rotation long term, as he has posted 1.3 fWAR over 120 ¹⁄₃ innings this season. That’s better than most expected, and roughly league average level or production. Norris’s slider is his only plus pitch at this point, but the changeup has shown improvement recently. Still, unless Norris finds a little more heat on the fastball this offseason — or at least a way for it to miss more barrels — his hold on a starting role will be tenuous as new options emerge from the farm. Let’s send Norris over to the bullpen in this hypothetical (he will be under contract for one final year come 2021).

Finally, we have Spencer Turnbull. Turnbull is currently The Athletic’s third-place pick in the American League Rookie of the Year race, and it’s not hard to see why. The 26-year-old righthander has posted 2.3 fWAR and a 3.75 ERA to match with a good strikeout rate (21.8 percent), a solid walk rate (nine percent), and a very low home run allowance rate (0.8 per nine). Turnbull’s 81 ERA- suggests he’s a solid bit better than the average major league pitcher, and his 84 FIP- asserts that it isn’t just luck. The orange-haired rookie may be turning 27 in September, but the Tigers will have him under a team-friendly contract for as he approaches his mid-30s. If there’s one player who should be be a lock — health permitting — for the future roster, it’s Turnbull.

That leaves us with the prospects. Here are the Tigers’ pitching prospects, per MLB Pipeline, their expected future value, and their rank on the MLB Pipeline list (with an estimated time of arrival in Detroit of 2021).

It’s important to keep in mind that prospects fail more often than they succeed, and pitching prospects are more prone to failure than hitting prospects, as this great article from Royals Review points out.

With that in mind, a higher prospect rank obviously correlates with success. So, let’s assume Casey Mize, the No. 2 prospect in all of baseball, has a very good chance of panning out, and No. 28 prospect Matt Manning also has a great shot. Additionally, we’ll assume Tarik Skubal does as well, as he has rocketed from obscurity onto the list and will likely be higher come 2020 preseason rankings.

Even if one or two of them do not work out, the Tigers have 10 other starting pitching prospects in their top 30, and nine of the 10 are projected to have a 45 Future Value (50 being league average) or better. Most of those guys will be sent to the bullpen in a moment — and we’ll have to assume a couple are so bad, or so racked by injury, that they can’t even stick there — but for the sake of the hypothetical, let’s say one of these guys can cement a spot in the rotation long term.

If we ignore all the factors I just mentioned and just purely ride the prospect hype train, we may end up with a rotation similar to:

1. Casey Mize
2. Matthew Boyd
3. Matt Manning
4. Spencer Turnbull
5. Tarik Skubal

Let’s say one of our three prospects doesn’t pan out in the rotation, that one guy isn’t as good as advertised, and that one of the non-top-100 prospects sneaks in and is better than advertised (let’s get crazy and say Joey Wentz is our guy, as he is a 50 FV prospect with no real injury issues or velocity concerns, unlike Franklin Perez or Alex Faedo). Then we may end up with something like:

1. Casey Mize
2. Matthew Boyd
3. Spencer Turnbull
4. Matt Manning
5. Joey Wentz

That’s a clean rotation. Even the Tigers were to deal Boyd in this hypothetical, they could sign a cheap starting pitcher to round things out or perhaps another prospect will make the rotation.

But wait! Aren’t we forgetting someone? Someone who won the 2016 American League Rookie of the Year? The plumber guy? Ah, yes, I remember him: Michael Fulmer.

You know what? Let’s say Fulmer, who posted back-to-back 3+ fWAR seasons to begin his career, comes back from Tommy John, as an overwhelming majority of pitchers do, to pitch in the rotation again. That gives us the following rotation:

1. Casey Mize
2. Matthew Boyd
3. Spencer Turnbull
4. Michael Fulmer
5. Matt Manning

Despite prospects having low odds of becoming stars, the Tigers have such strong pitching depth that they should be able to create a fully home-grown rotation. In doing the legwork of looking forward to the future, we’re able to see that there is definitely a light at the end of the tunnel when it comes to the Tigers starting rotation.

However, can they build a home-grown bullpen with the misfits?

We’ll take a look at the bullpen next.