Valera, who doesn’t turn 19 until May 18, reached 100 mph with his fastball Friday when he pitched against the Twins prospects in the Futures at Fenway South game here at JetBlue Park.

Valera was the youngest prospect on the Red Sox’ Breakout Game roster against the Rays prospects on Thursday. He didn’t pitch in that game but he struck out four in 3 innings in the Red Sox’ 6-4 win over the Twins prospects Friday.

Valera posted a 1.99 ERA, 0.85 WHIP, .125 batting average against, 68 strikeouts and 28 walks in 18 outings (16 starts) and 63 ⅓ innings between the Florida Complex League Red Sox and Low-A Salem in 2024. He had a 2.35 ERA and held opponents to a .120 batting average in seven starts (23 innings) at Salem.

The baseball world has started to take notice. He made a huge leap last year, going from unranked on SoxProspects.com’s Top 60 to its No. 19 prospect now.

MassLive ranks Valera the No. 14 prospect in Boston’s system. Baseball America also ranks him 14th in the system. MLB Pipeline ranks him No. 18.

Asked about his rise on prospect lists, he said, “It feels really good but I’m trying not to focus too much on that and just working as hard as possible.”

Senior director of player development Brian Abraham described Valera as a “big body starting pitcher” (6-3, 205 pounds) with a “really good fastball.”

“Still working on his secondaries, trying to expand that pitch mix,” Abraham said last month. “But he throws them all for strikes, pounds the zone, attacks. I think again, just trying to work on his pitch mix, ability to tunnel pitches.”

Valera throws a slider, sweeper and changeup in addition to his heater. He considers his sweeper his best secondary pitch right now.

Valera said he began throwing a sweeper as an amateur. He signed with Boston out of the Dominican Republic as a 16-year-old on April 12, 2023, for just $45,000.

“I’ve been throwing that pitch from the very beginning of being a pitcher,” Valera said. “Before I signed with the Red Sox. When I got here, I started practicing more to make it more nasty.”

He’s focusing heavily on improving his slider right now.

“I’m experimenting right now and trying to throw a gyro slider as well,” he said.

“It’s a pitch I’ve been working on for a minute,” Valera added. “It’s a pitch I want to work on to be able to land to start at-bats and also later on in the at-bat.”

His changeup is considered his fourth best pitch at the moment.

“Just taking off some speed so that I can get hitters off of the fastball and get more ground balls,” Valera said.

Valera said he also continues to focus on his mechanics.

“Working on being more fluid and just working on my routine,” he said. “My mechanics and routine.”

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