FORT MYERS, Fla. — Red Sox top pitching prospect Bryan Mata throws a mid-90s fastball and added a swing-and-miss slider to his repertoire last spring, helping him improve his command considerably.

He’s only 20 and he struggled in several starts after his promotion to Double A last year. But he has high expectations for himself entering 2020.

“My goal is to obviously pitch in the major leagues this year,” Mata said through translator Bryan Almonte. “But all I can control is my performance. Wherever the team feels like it’s best for me to pitch to start the year, that’s fine. But I know I’ll keep working hard so I’ll eventually get up to the major leagues this year.”

Mata is here at JetBlue Park participating in his first big league spring training camp. He’s expected to begin 2020 at Double-A Portland. Boston must add him to its 40-man roster by next November to protect from the 2020 Rule 5 Draft.

He dominated at High-A Salem with a 1.75 ERA, .201 batting average against, 1.09 WHIP, 52 strikeouts and 18 walks in 10 starts (51 ⅓ innings) to begin the 2019 season. He then struggled in some of his starts after a promotion to Double-A Portland (5.03 ERA, 11 starts, 53 ⅔ innings), but he was one of the youngest pitchers in the Eastern League.

Baseball America ranks the righty Boston’s top pitching prospect. It lists him as the No. 4 overall prospect in the system behind position players Triston Casas, Bobby Dalbec and Jeter Downs.

He throws a four-seamer, two-seamer, slider, curveball and changeup. Baseball America noted “he has No. 3 starter potential.”

“It’s something I worked hard on during the spring last year to incorporate that slider,” Mata said. “And it really helped me a lot in the season because I was able to get a lot of swing-and-misses and also a lot of soft contact when they did hit it.”

Per his Baseball America scouting report, “The Red Sox determined that his arm slot was better suited to a two-seamer as a primary offering.” He began throwing his two-seamer more in 2018 and struggled with command.

But he showed much better command in 2019. He averaged 3.6 walks per nine innings in 2019, down considerably from 7.3 walks per nine innings in 2018.

Meanwhile, his strikeout percentage increased from 7.6 per innings innings in 2018 to 9.5 last year.

“It was mostly just my confidence in that pitch (slider), especially when I got behind 2-0 or 3-1 (in the count),” Mata said. “Being able to throw that pitch — and guys expecting it to be a fastball — and instead it was a slider, it really helped me with my confidence and being able to get batters out. Because I knew I had that pitch to be able to bail me out.”

His two-seamer helped him post a 65.9% groundball percentage at Salem and 52.1% groundball percentage at Portland in 2019.

“I really focused on working on my mechanics (this past offseason) to be a little bit more consistent with my control,” Mata said. “That’s something I really worked on because I feel like that was lacking.”