Although most pitching prospects begin their minor league careers as starters, many of them eventually wind up in the bullpen at the MLB level. The Minnesota Twins are very familiar with how this transition can lead to a fruitful career with the likes of Joe Nathan, Glen Perkins, and, more recently, Tyler Duffey doing so under their watch.
The Twins currently have a multitude of pitching prospects who are knocking on the door to the majors, but it is unlikely that all of them will stick as starters. Below are five names who could not only make the switch to the pen, but may ultimately perform well in the closer role.
RHP JHOAN DURAN
2021 stats (Triple-A): 5 G, 4 GS, 16 IP, 5.06 ERA, 3.86 FIP, 22 K, 13 BB, 16.7% HR/FB
Duran has, without a doubt, the most electric raw stuff in the Twins' farm system. He regularly hits 100 mph with his 4-seam fastball, which pairs well with his splitter-sinker hybrid (low-90s) and curveball (mid-80s).
However, his poor command and right upper-extremity injury history may limit the overall height of his ceiling; he’s only ever thrown more than 70 innings in a season once.
There are many similarities between Duran and former Twin Brusdar Graterol, so it would not be surprising to see their careers take indistinguishable paths. Graterol was solid out of the pen for the Los Angeles Dodgers in 2021, though he functioned more as a set-up man than a closer.
A shift to the bullpen may be in Duran — and the Twins' — best interests in the short and long-term.
RHP LOUIE VARLAND
2021 stats (Low-/High-A): 20 G, 18 GS, 103 IP, 2.10 ERA, 2.34/3.20 FIP, 142 K, 30 BB, 6.9%/5.8% HR/FB
The Twins' 2021 Minor League Pitcher of the Year burst forth out of obscurity this past summer on the back of a fastball that jumped in average velocity from the low-90s while at Division II Concordia University, St. Paul to the mid- to upper-90s with above average spin.
He also owns a biting curveball that plays well down in the zone, feeding off the dominance of his fastball up. However, he lacks a third pitch and, despite low walk numbers, occasionally struggles with command, particularly that of his breaking ball.
Varland will likely stick in a starting role as he advances through the minor leagues, but unless he develops a third offering or cleans up his curveball, his future may be as a back of the bullpen ace. The Twins have had previous success with closers from St. Paul, after all.
RHP OSIRIS GERMAN
2021 stats (Low-/High-A): 38 G, 0 GS, 4 SV, 59 1/3 IP, 3.34 ERA, 3.14/2.69 FIP, 90 K, 24 BB, 12.5%/4.5% HR/FB
At just 23 years old, German is still at least a couple of years away from sniffing the majors, but it’s easy to see why he is highly thought of after watching just a couple of pitches. German has that undefinable, yet important electricity that many of the game’s best bullpen arms possess.
While his fastball pops out of the hand and plays well up in the zone, it’s his breaking ball that is the star of his show.
What may prevent German from reaching his potential, however, is his erraticism and high-effort delivery. German doesn’t possess good command of either his fastball or curve, often overthrowing both. From a mechanics perspective, doesn’t get enough push off from his lower extremity which causes him to rely on the whipping action of his core and shoulder to produce torque and velocity
German is the perfect candidate for a tweak in his delivery as well as the development of a third pitch (perhaps a cutter?). If he can hone his command, his stuff is good enough to reach the majors.
RHP COLE SANDS
2021 stats (Double-A): 19 G, 18 GS, 80 1/3 IP, 2.46 ERA, 3.55 FIP, 96 K, 35 BB, 7.2% HR/FB
Sands was among the Twins’ most steady minor league starting pitchers in 2021. He consistently pitched until at least the fifth inning and racked up strikeouts with the best in the system, ranking ninth overall.
The former Florida State Seminole has a three pitch mix consisting of a fastball, curve, and changeup, though only his breaking ball is currently an above average offering. (His fastball is close, and may already be there, depending on whose opinion you seek.)
In many respects, Sands is a carbon copy of current Twins’ reliever Tyler Duffey, who has been among the team's more consistent bullpen arms over the past couple of seasons.
Sands currently may lack an electric fastball — which is often a requirement among back of the bullpen arms — but his curveball and punch out pedigree is intriguing.
HIBERNATION CANDIDATE: LHP AARON ROZEK
2021 stats (Rookie Ball through Double-A): 16 G, 7 GS, 56 1/3 IP, 2.40 ERA, 0.81/2.48/4.40/2.15 FIP, 74 K, 7 BB, 0.0%/14.3%/18.2%/0.0% HR/FB
Rozek came out of nowhere during the 2021 season. The Burnsville native and Minnesota State University, Mankato alum signed with the Twins on a minor league deal in late June before proceeding to pitch to great success across four levels of play. (He had never played in the minors prior to his signing, though he did play Indy Ball during 2019.)
Rozek possesses two breaking pitches — a slider and a loopier slurve — which he uses primarily as his out pitches as well as a a fastball, though it is rather mediocre.
At age 26 with less than one season of MiLB experience under his belt, the likelihood Rozek ever makes it to the parent squad is slim. Add in the fact that he is left-handed and doesn’t possess an elite fastball, and the odds of him ever being a closer are nearly nil. But for an undrafted free agent from an NCAA Division II school, he displayed plenty of talent that should pique the interest of Twins’ fans.
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