When the A’s drafted Jefferies with the 37th overall selection in the 2016 Draft, they felt the Cal product was the type who could move very quickly through their system because of his outstanding command and extremely advanced feel for pitching. Though he had answered questions about a shoulder issue by returning to the mound and pitching well down the stretch during his junior year, it was actually his elbow that kept the A’s from finding out just what Jefferies could do. Tommy John surgery kept him off the mound for nearly two seasons, but he returned in 2019 and lived up to that billing, reaching Double-A and earning a spot on the 40-man roster as a result.
Not only did Jefferies stay healthy in 2019 as the A’s closely monitored his workload, his stuff and command came back, allowing him to post a ridiculous 93/9 K/BB ratio over 79 innings of work. He’s likely going to work with a low-90s fastball, around 91-93 mph, though he can reach back for a 94 now and again and it plays up because of his ability to command it so well. He complements it with a plus changeup that he sells really well with his arm action and good tunneling with excellent fade that drops off the table right at the end.
He’s never had a great breaking ball and he’s experimented with different pitches and grips. He didn’t throw it a lot in 2019 and it was inconsistent, looking like a slider-cutter hybrid more often than not. If he can commit to a breaking ball to give him a third average offering, he has the chance to be a No. 4 type starter in short order, a kind of Kyle Hendricks type with a bit more velocity.
Scouting grades: Fastball: 60 | Slider: 50 | Changeup: 55 | Control: 55 | Overall: 45
Jefferies answered questions about a shoulder injury during his junior season at California when he came back and pitched well leading up to the Draft. The A's were convinced and took him with the No. 37 pick in 2016. His career in the organization has barely gotten started as he needed Tommy John surgery after just two outings and has logged just two Rookie-level innings since.
Jefferies did participate in mini camp as the 2019 season approached and the ball was coming out of his hand well. His velocity was up to 90-91 mph in bullpen sessions and he'd shown excellent command of his low-90s fastball in the past. His changeup has the chance to be a plus pitch, thrown with terrific deception, and the bottom falls out of the pitch. His slider looks more like a cutter to some and it has more teeth that way, with the A's wishing he would have a little more finish on the end of it to turn it into a better-than-average pitch.
Jefferies was always known as a strike-thrower before the injury, and he got back to filling up the zone in 2019. After good post-surgery progress, he's attacking the organizational ladder in earnest.
Jefferies appeared to be on his way toward becoming a first-round pick in the 2016 Draft after a strong start to his junior season at California, only to miss most of April and May with a shoulder injury. But after he returned healthy and dominated in the weeks before the Draft, the A's felt good enough about his medicals to take him in Lottery Round A with the 37th overall pick. Assigned to Class A Advanced Stockton for his first full season, Jefferies logged just two starts before it was announced he would need season-ending Tommy John surgery. He returned to the mound the following July and picked up where he'd left off, striking out five batters over two scoreless innings in the Rookie-level Arizona League.
When he's healthy, Jefferies will add and subtract from his heater, sitting comfortably in the low 90s but also reaching back for 95 mph, with feel for locating to both sides of the plate as well as down in the zone. His changeup is his best secondary pitch, a mid-80s offering thrown with fastball-like arm speed and late fading action, and he has the makings of a slider that should be at least Major League-average. A consistent, over-the-top release point allows him to create extension and angle toward the plate, and everything he throws plays up due to his advanced control and command. In general, Jefferies should miss even more bats with improvement to both his changeup and slider.
Jefferies is a good athlete with clean arm action and a repeatable delivery. But as an undersized righty with a checkered medical history, he'll need to prove he can handle the rigors of a full season on the mound. If he can do so, Jefferies' stuff, pitchability and deception could make him a No. 4 starter at the highest level. He's expected to return to game action sometime around the middle of the 2018 season.
Scouting Grades: Fastball: 60 | Slider: 50 | Changeup: 50 | Control: 55 | Overall: 45
Jefferies appeared to be on his way toward becoming a first-round pick in the 2016 Draft after a strong start to his junior season at California, only to miss most of April and May with a shoulder injury. But he was able to get back on the mound and prove that he was healthy in the weeks before the Draft, and the A's felt good enough about his medicals to take him in Lottery Round A with the 37th overall pick. They assigned him to Class A Advanced Stockton for his first full season, but Jefferies made just two starts before it was announced he would need season-ending Tommy John surgery. </p>
Jefferies can add and subtract from his heater, sitting comfortably in the low 90s but also reaching back for 95 mph, with feel for locating to both sides of the plate as well as down in the zone. His changeup is his best secondary pitch, a mid-80s offering thrown with fastball-like arm speed and late fading action, and he has the makings of a slider that projects to at least Major League-average. A consistent, over-the-top release point allows him to create plane towards the plate, and everything he throws plays up due to his advanced control and command. Meanwhile, scouts expect Jefferies to miss more bats with improvement to both his changeup and slider. </p>
Jefferies is a good athlete with clean arm action and a repeatable delivery, though as an undersized righty, he'll need to prove he can physically handle the rigors of a full season on the mound. He'll miss the remainder of the 2017 season, as well as some of the following year, but Jefferies possesses the stuff and pitchability to become a No. 4 starter in the big leagues.
Scouting Grades: Fastball: 60 | Curve: 50 | Changeup: 50 | Control: 55 | Overall: 50
Despite his stature -- Jefferies is just six-feet tall -- he was moving up boards at the start of the spring as the most consistent performer among college pitchers in this Draft class. But after six dominant starts, Jefferies missed his first start in April with what was originally thought to be a calf strain. When news circulated that it was actually a shoulder issue, it threw his Draft status way up in the air. However, the A's felt good enough about Jefferies' medicals to offer him a $1.6 million bonus after taking him in Lottery Round A with the 37th overall pick.
When healthy, Jefferies uses a compact delivery that helps him bring fastballs up to 95 mph to the plate. He can add and subtract from his heater, sitting most comfortably in the low-90s. Jefferies throws his slider across his body, and it serves as more of a chase pitch right now. He doesn't use his changeup that much, but it has good sink and has been effective against left-handed hitters at times. A former shortstop, Jefferies fields his position very well and is extremely competitive on the mound.
Jefferies did return at the end of May to throw eight scoreless innings over two outings, giving him some late traction up draft boards. For now, the A's are having him work out at the team's complex in Arizona as he continues to recover from the shoulder injury. So long as he remains healthy, Jefferies could develop into a Mike Leake or Jeremy Hellickson-like undersized right-handed starter in the big leagues.