Red Sox pitching prospect Ryan Zeferjahn tosses 3 scoreless innings in first career relief appearance for High-A Greenville

Red Sox pitching prospect Ryan Zeferjahn made the first relief appearance of his professional career for High-A Greenville on Wednesday night. Making his season debut for the Drive, the right-hander allowed just one hit and struck out two over three scoreless — albeit low-leverage — innings of work.

Zeferjahn needed just 35 pitches (24 strikes) to retire nine of the 10 batters he faced while earning the win in Greenville’s 17-3 trouncing of the Asheville Tourists (Astros affiliate) at McCormick Field.

The Red Sox originally selected Zeferjahn, now 24 years old, in the third round (107th overall pick) of the 2019 amateur draft out of the University of Kansas. At that time, Zeferjahn was regarded by Baseball America as the 57th-ranked draft-eligible prospect. The Topeka native signed with the club for $500,000.

Upon signing his first pro contract, Zeferjahn was assigned to short-season Lowell out of the gate and made 12 starts for the Spinners to close out the year. Coming into the 2020 season, the former Jayhawk was ranked by Baseball America as the No. 19 prospect in the Sox’ farm system.

Unfortunately, the 2020 minor-league season was wiped out on account of the COVID-19 pandemic, so the only real in-person guidance Zeferjahn received from the Red Sox that year came later on at fall instructs.

Falling out of Baseball America’s Boston prospect rankings the following spring, Zeferjahn broke camp with Low-A Salem. He posted a dismal 6.91 ERA — but much more encouraging 3.86 FIP — to go along with 41 strikeouts to 15 walks over 12 starts (41 2/3 innings pitched) for Salem before being sent down to the Florida Complex League in mid-July.

According to’s director of scouting Ian Cundall, Zeferjahn was sent to Fort Myers in order to work on his mechanics. He made four starts for the FCL Red Sox beginning on August 31 and pitched to the tune of a 3.21 ERA and 4.29 FIP with 18 strikeouts to three walks across 14 innings of work.

Listed at 6-foot-5 and 210 pounds, Zeferjahn operates with a four-pitch mix that consists of a 93-95 mph fastball with sink, an 84-87 mph slider, an 83-86 mph changeup, and a 76-80 mph changeup, per his scouting report.

Before the 2022 season began last week, Zeferjahn had only been used as a starter throughout his pro career as he made 28 starts between three different levels from 2019-2021. The last time the righty was used out of the bullpen came in the summer of 2017, when he made 13 appearances for the Falmouth Commodores of the Cape Cod Baseball League.

When used in shorter stints, though, it appears as if Zeferjahn can further tap into his fastball velocity. While information from Wednesday’s outing is not currently available, Zeferjahn did reach 98 mph with his heater when making starts of one to three innings with Lowell in 2019.

Zeferjahn, who turned 24 in February, comes into the 2022 campaign not ranked by any major publication as one of the top pitching prospects in the Red Sox organization. He can, however, become eligible for the Rule 5 Draft for the first time in his career this winter.

(GIF of Ryan Zeferjahn via the Greenville Drive)

Jaxx Groshans evaluates some of the top pitching prospects in the Red Sox farm system

He’s caught them. He’s hit against them. When it comes to some of the more intriguing pitching prospects in the Red Sox organization, there aren’t many better people to ask about them than catching prospect Jaxx Groshans.

When speaking with earlier this week, the 22-year-old backstop shared his thoughts on the likes of Jay Groome, Noah Song, and Ryan Zeferjahn, all of whom are regarded by as top-15 pitching prospects within Boston’s farm system.

Here are those thoughts put into writing.

LHP Jay Groome (SoxProspects’ No. 7 pitching prospect)

“I’ve faced off against Groomy multiple times and I got to catch him when I was in Lowell and at fall instructs both years (2019 and 2020). His stuff has grown a long way, man. He’s got big-league caliber shit, and I think that’s going to carry him for a while.”

RHP Noah Song (SoxProspects’ No. 6 pitching prospect)

“I caught Noah in his debut in Aberdeen… As far as Songy is concerned, that’s some of the best pure stuff I think I’ve ever seen. I applaud him for going back and serving [in the Navy] like he was supposed to, but that’s a damn shame because that kid probably could have been in the big-leagues this coming year. He probably could have made an appearance in the league out of the ‘pen last year to be honest with you, because his stuff is that good.”

RHP Ryan Zeferjahn (SoxProspects’ No. 11 pitching prospect)

“Zef’s a good dude, man. He’s got some electric stuff, too. I’m very, very excited to see how his career pans out because I think he can be a successful big-leaguer for a long time, especially if he figures out control of all his pitches and finetunes them. We’ll just have to wait and see from here. Like I said, he’s got a lot of special stuff and he’s very blessed with the arm he has.”

Groshans and Zeferjahn both played college baseball together at the University of Kansas. They were both selected by the Red Sox within hours of each other during Day 2 of the 2019 MLB first-year player draft.

“Before we got drafted, we were in Bricktown (Oklahoma City) playing Kansas State in the Big-12 tournament,” Groshans recalled. “Me and Zef were sitting on the bench, and Zef was like ‘Man, how cool would it be if the both of us got drafted by the same team? It would be sick because I’d get to throw to you and we’d be teammates again.’

“And I was like ‘Yeah, dude. That would be sick. That would be awesome,'” continued Groshans. “Then I saw Zef got picked by the Sox in the third [round], and I was like ‘Damn, okay. What’s going to happen? How’s this going to go?’ Then my agent texted me and he was like ‘Red Sox.’ So, I kind of kept it in for a second and as soon as my name got called, Zef was one of the first people to text me. He was like ‘Let’s freaking go! That’s awesome, man!’ I was like ‘Yeah, meet me in Florida and let’s have some fun.'”

BONUS: Former University of Oklahoma outfielder and Oakland Athletics first-round draft pick Kyler Murray, who is currently the starting quarterback for the NFL’s Arizona Cardinals

“I know Kyler. I grew up around the same area — before I moved to Houston — that he was from. So I was from Plano, he was from Allen (Texas). I met him off and on the field, too. He’s a freak athlete, man.

“I saw something the other day where they were putting out on SportsCenter: Who of these NFL athletes would be successful in the minor-leagues if they played?’ It’s Kyler 100% hands down,” Groshans said. “He’s said it before. I don’t believe his time in baseball is done yet. I think if at any point he decides to come back, he could definitely do it. 100%.”

(Picture of Jaxx Groshans: Kelly O’Connor/