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2018 BYB Tigers prospect #21: RHP Spencer Turnbull is still worthy of your attention

Injuries have slowed Turnbull’s progress so far, but the big righty still has starter potential.

Detroit Tigers Workout Photo by Mark Cunningham/MLB Photos via Getty Images

Admit it: you probably forgot about Spencer Turnbull at some point over the past couple years. The Detroit Tigers’ second round pick in 2014, Turnbull has only compiled 313 innings in four years due to injuries. He only just reached Double-A last season, and only made four starts for the Erie SeaWolves to boot. A normal progression through the minors would see him on the cusp of the majors right now, if not already entrenched in the Tigers’ rotation.

Amazingly, these setbacks have hardly dimmed his prospect status. He was never expected to be a frontline starter, but rather a mid-rotation workhorse with an iffy changeup and command. For the most part, this is still the case. We might have to downgrade expectations to “No. 4 or 5 starter,” but that’s impressive buoyancy for a player who has already endured a serious shoulder injury in his career.


Turnbull was Alabama’s Friday night starter for parts of two years in college, logging 90-plus innings in both his sophomore and junior seasons. He didn’t strike out many batters, but posted a 2.22 ERA in 15 starts as a junior. This put him on the Tigers’ radar, and they selected him with their second round pick of the 2014 draft. The Tigers treated him with kid gloves down the stretch in 2014, limiting him to just 28 13 innings across 11 starts.

In 2015, Turnbull showed promise with the Single-A West Michigan Whitecaps, limiting opponents to a 3.01 ERA in 116 23 frames. He didn’t get a chance to follow up on that campaign, though. Turnbull missed the first two months of 2016 with a shoulder impingement injury, and his innings were significantly limited thereafter. He totaled just 73 innings in 2016 (including 20 frames in the Arizona Fall League), and an elbow injury held him to 112 innings in 2017. He showed promise during the bulk of last season, though, pitching to a 3.05 ERA while lowering his walk rate in 15 starts for High-A Lakeland.


Even though the shoulder injuries have sapped his velocity somewhat, Turnbull’s fastball is still his bread and butter. He sits in the lower-to-mid 90s now, throwing 92-94 miles per hour during most starts. TigsTown’s Mark Anderson says Turnbull can still ramp the heater up to 96 mph — and Baseball America’s Josh Norris clocked him a tick faster in August — but that’s a step back from the near-triple-digit heat he featured out of college. At its best, the fastball is like a bowling ball, helping him generate plenty of weak groundouts. He featured a 51.7 percent ground ball rate at Lakeland last year, and has been at 50 percent or better in each of his minor league stops.

Even the drop in fastball velocity can be seen as somewhat of a strength. Without so much heat on the fastball, Turnbull has improved his command. He posted a walk rate north of 10 percent in that otherwise solid 2015 season with the Whitecaps, and wasn’t much better in college. Since the injuries forced him to dial back slightly, Turnbull has lowered his walk rate considerably; he was at just 7.6 percent in High-A last year, and that only regressed slightly when he moved up to Double-A at the end of the season. Baseball Prospectus echoed this improvement in their preseason write-up, praising Turnbull’s “feel to pitch” as a reason why he could stick in the rotation.

Turnbull’s mechanics have also taken a big step forward over the past few years. Baseball America’s Josh Norris came away very impressed when he saw Turnbull pitch* last August, and detailed a few specific tweaks to the righty’s once-wonky delivery.

In order to improve that command, Turnbull made a few minor tweaks in his delivery. Specifically, he’s worked hard to stay more on-line to the target. He’s adjusted his stride to land more closed before when he delivers instead of flying open frequently, like he did at Alabama.

Norris also called him “more of a pitcher,” which is the kind of comment we hope to see about any raw, hard-throwing prospect.

*Turnbull out-dueled Phillies top prospect Sixto Sanchez that day, striking out five while allowing one earned run in eight innings.


Once one of his biggest strengths, Turnbull’s slider is now a bit of a worry. It used to be a true wipeout offering, one capable of helping him rack up healthy strikeout totals. Now, with the aforementioned drop in velocity, the slider has taken a step back. Baseball Prospectus noted that he still commands it well...

This fall, the cutter and slider were blending, but the latter (82-86 mph) showed flashes of a swing-and-miss offering with sharp late action, and he commanded it better than both the cut-piece (86-87 mph) and below-average cambio.

...but also surmised that “there is not an out-pitch of the bunch at present.” For a pitcher of Turnbull’s past pedigree, one would hope the slider would be a bit more consistent at this point. It’s possible he turns things around — as mentioned, it used to be a weapon — but it’s also possible he could struggle to miss bats as a starter.

Speaking of iffy off-speed pitches, Turnbull’s changeup has always been a long-term project. TigsTown’s Mark Anderson notes that the pitch has improved over the past couple years, calling it “borderline average” now. Baseball Prospectus was a bit more pessimistic, while other publications haven’t even ranked Turnbull at all. The changeup will be crucial for Turnbull to develop in order to keep lefties off his fastball. To his credit, it seems like he’s moving in the right direction.

Projected team: Double-A Erie SeaWolves

Turnbull is entering his age-25 season in 2018. He won’t ever rocket up the Tigers prospect radar, but has enough raw talent to still be in their rotation mix in the near future. He has also improved on some of his draft day weaknesses, and should be competitive as he gets his first real crack at the high minors. This isn’t a make-or-break season for him as a prospect, but he could certainly put himself on the call-up radar for 2019 with a strong performance this year.