The Yankees signed right-hander Adonis Rosa out of Santiago, Dominican Republic on December 19, 2013, as an international free agent.
Rosa made his professional debut in 2014 as a member of the Dominican Summer League Yankees. The 6-foot 1-inch tall native of Santiago, Dominican Republic appeared in 12 games that season, making three starts, and earned a 1.62 ERA in 39 innings.
His strong performance in the Dominican Republic earned him a promotion state-side to the Pulaski Yankees of the Appalachian League in 2015. As a regular of the Pulaski rotation, he had a 7-2 record with a 3.93 ERA in 55 innings over 11 games.
Rosa started the 2016 season in extended spring training before reporting to Staten Island to start the New York-Penn League season in June. Rosa was the opening day starter for the Staten Island Yankees, allowing two runs over six innings and striking out six Cyclones. He went on to earn a 2-1 record with a 1.32 ERA in six games, five starts, striking out 27 over 34 innings with the Baby Bombers.
He earned a promotion to the Charleston RiverDogs on July 22, 2016. With the RiverDogs he owned a 2-5 record with a 2.86 ERA in eight starts. He struck out 46 over 44 innings. He ended his season with a six-inning shutout on September 1 against Hagerstown.
Rosa split the 2017 season between three different teams, including a brief two-game cameo in Triple-A with the RailRiders. Overall, he had an 8-3 record with a 3.06 ERA and 102 strikeouts in 111 2/3 innings pitched over 26 games, 13 starts.
He spent most of the season with the Single-A Charleston RiverDogs of the South Atlantic League where he was 4-3 with a 3.04 ERA in 21 games, eight starts, striking out 79 batters in 83 innings pitched. He had three games with the Tampa Yankees, winning all three and pitching to a 4.32 ERA with 16 strikeouts in 16 2/3 innings. In his two games in Triple-A, Rosa allowed just two earned runs in 12 innings of work, striking out seven.
Rosa went 14-6 with a 3.93 ERA in 26 games, 21 starts, with 108 strikeouts in 128 1/3 innings in 2018. He led the entire Yankees organization with 14 victories and was third in the organization in innings pitched. His 128 1/3 innings was a career high.
The bulk of his 2018 season came in High-A with the Tampa Tarpons where he went 12-3 with a 3.84 ERA in 20 games, 15 starts. He had a quick two-game cameo in Double-A with the Trenton Thunder where he allowed six earned runs in 11 2/3 innings before ending his season in Triple-A with the RailRiders. With Scranton, he went 2-1 with a 3.92 ERA and 13 strikeouts in 20 2/3 innings of work over four games.
Unlike many of the pitchers in the Yankees system, he does not throw 98 miles per hour. He relies heavily on plus command of his four pitches and competitiveness that matches up with anyone in the system.
His fastball usually sits 91-93 miles per hour, occasionally getting it up to 94 at times. He follows it up with an average curveball and slider as well as a changeup that is still developing and clearly lags behind his other pitches.
Rosa will most likely begin the 2019 season as a member of the starting rotation for the Trenton Thunder. If he continues to have the success he had throughout his career a promotion to Triple-A would not be out of the question.