Breakout Red Sox pitching prospect Anthony Eyanson acknowledged curiosity last week. After an overpowering start to his professional career with High-A Greenville, when might he be ready for the first promotion of his big league career?
“The human element, for sure I think about that,” Eyanson said on Thursday. “But I just try to remind myself to stay grounded, be where your feet are, and everything will play out as it should.”
His patience was rewarded on Sunday. According to a major league source, the Sox informed Eyanson that he’s moving up to Double-A Portland. That decision was made after the righthander posted video game numbers in a handful of outings in Greenville.
In five starts spanning 20⅓ innings for the Drive, the 21-year-old posted a 0.44 ERA with 34 strikeouts (a 48 percent strikeout rate) and three walks while holding hitters to a .104/.155/.149 line. He didn’t allow a run in his last four starts.
Has he been surprised by the results?
“Absolutely not,” said Eyanson. “I think [the results] just represent my hard work and everything that I’ve put into being a better pitcher [since entering pro ball].”
It’s one of the most dominant career starts in years by a Red Sox draftee — at least since Matt Barnes, who in 2012 began his pro career with a 0.34 ERA and 42 strikeouts in 26⅔ innings in Low-A. It’s the sort of performance that suggested a need to challenge Eyanson with more advanced competition.
“He just hasn’t been punched in the face yet,” Red Sox director of pitching Ben Buck said prior to the decision to promote Eyanson. “You expect [pitchers] to hit kind of a bump in the road right out of the gate. He just hasn’t found that yet, so you start thinking, the adjustments we made entering the season have elevated him past that level.
“You want to find the next level that’s going to punch him in the face and force him to adapt and overcome. That’s how he’s going to develop.”
Eyanson already has made huge developmental strides since the Sox took him in the third round out of LSU last year. Eyanson had been a tremendous college performer, going 12-2 with a 3.00 ERA and 34 percent strikeout rate — a year punctuated with a College World Series title.
Still, while his curveball and slider overpowered opponents, both the low-90s velocity and lack of carry on his fastball capped his draft stock.
“It was just a dead-zone heater,” said Buck. “His whiff in college on his heater wasn’t that great. That was actually the knock on him.”
As Eyanson remained on the board, watching pitchers whom he’d outperformed in college getting selected in front of him, resolve formed.
“Understanding I was taken in the third round, 87th pick, I have it in my mind that every single MLB team passed on me more than once,” said Eyanson. “That just puts a huge chip on my shoulder, just trying to prove it to everybody, but most importantly, just proving it to myself, that I understand that I can be the person that I want to be and the pitcher that I want to be.”
That chip has been a catalyst for growth. Eyanson described himself as a “sponge” for instruction, and he has made leaps in his arsenal in the 10 months since he was drafted.
“He has, more than maybe anyone I’ve ever seen, this relentless obsession with better. It makes all these things that we’re doing really easy. It’s a rare trait,” said Buck. “That just bleeds over into his work. He lifts like a monster. He throws like a monster. It’s awesome.”
Once he signed, Eyanson immediately embraced the team’s strength and conditioning program as well as velocity training, allowing him to sit at 95-97 miles per hour this year. He also raised his arm slot to create an average release height of about 6½ feet, similar to pitchers Nick Pivetta and Michael Wacha.
That high release height has allowed him to better stay behind the ball when throwing fastballs, creating significantly improved carry on the pitch. He averages 18 inches of fastball ride this year, up significantly from college.
He combines that with a high-spin curveball in the 80-m.p.h. range that averages 15-16 inches of dive, along with a slider and splitter in the mid- to high-80s. He’s made particular strides with a diving splitter that tumbles toward the plate at about 1,000 RPMs. (“If you were looking on a [slow-motion camera], you wouldn’t be able to distinguish it from a knuckleball,” said Buck.)
“I understand my arsenal. It’s very vertical,” said Eyanson. “I think north-south, and just keeping stuff over the plate and in the zone. I’m trying to throw everything in the zone and just let the pitch move on its own and let the hitter give himself his own problems.”
In High-A, hitters couldn’t solve the problems. Now, with Eyanson heading to Portland, Eastern League hitters will get their shot — with the Sox on notice that Eyanson has shown immediate characteristics of a pitcher who can push the envelope in his development.
“We did the same thing with [Payton] Tolle last year, and he just kept moving,” said Buck. “You keep doing that in case the level that they need to find is the big leagues.”
Three up
⋅ A name worth monitoring as a potential bullpen option in Triple-A: Righthander Angel Bastardo, returned to the Red Sox from the Blue Jays after spending more than a year with Toronto recovering from Tommy John surgery, is throwing well for the WooSox. In two appearances, he’s thrown five shutout innings with eight strikeouts and four walks, with particular dominance against righties (1 for 12, seven strikeouts, no walks).
⋅ Middle infielder Yoeilin Cespedes, 20, has been on a tear in Greenville, hitting .323/.384/.692 with six home runs and 12 extra-base hits in his last 15 games.
⋅ Two-way player Conrad Cason, a 19-year-old who is playing games solely as a position player this year while rehabbing from Tommy John surgery, hit a pair of homers on Opening Day in the Florida Complex League. He’s DH-ing for now but is expected to play shortstop once cleared.
Three down
⋅ While Mikey Romero had shown improved at-bat management and bat-to-ball traits to start the year (10 percent strikeout rate through 10 games), he’s fanned in 29 percent of plate appearances over the last 19 contests. The 22-year-old is hitting .241/.315/.321 for the season.
⋅ While Portland righthander John Holobetz has shown an improved ability to get swings and misses this year, most notably in an 11-strikeout performance on April 18, he’s been vulnerable to loud contact, allowing five homers in 25⅔ innings this season.
⋅ Righthander Kyson Witherspoon has struggled to harness his strong mix in the strike zone in his pro debut with Greenville. The 2025 first-rounder has walked nine batters over six innings in his last two outings, and 14 percent of the batters he’s faced this year (with a 24 percent strikeout rate) with a 7.13 ERA.
Alex Speier can be reached at alex.speier@globe.com. Follow him @alexspeier.