Luis Jefferso Curvelo…hails from Higuerote, Venezuela…was ranked as No. 31 prospect in the Seattle organization by FanGraphs in July 2024.
2025
Went 1-1 with a 5.68 ERA (12 ER/19.0 IP), 1.42 WHIP figure, .236 opponents BA (17-for-72) and 20 SO/10 BB in 17 relief appearances for TEX across his first two career MLB stints: 7/30-9/15, 9/26-end of season…posted reverse splits, holding opposing lefties to a .194 (6-for-31) clip, while righties batted .268 (11-for-41)…produced a 25.9% ground ball rate (14 ground balls on 54 balls put in play) over his 17 games in MLB, the seventh-lowest mark among A.L. hurlers from 7/31-end of season, min 80 BF (Stats Perform)…pitched two SHO IP with three SO in MLB debut on 7/31 at SEA, 1st TEX reliever w/ 2.0+ SHO IP and 3+ SO in ML debut since Grant Anderson on 5/30/23 at DET (2.2 SHO IP, 7 SO)… in second MLB outing on 8/2 at SEA, earned first MLB victory (1.1 SHO IP, 1 SO), part of a 6-4 Rangers win in 11 inn…became the third pitcher in WSH/TEX franchise history to earn a relief W within his first two MLB appearances by finishing an extra-inning victory (also B. Manuel on 9/11/91 at CAL and D. Mathis on 5/12/08 vs. SEA)…scoreless in 10 of 17 G with TEX…five of 12 ER came in one outing, 8/8 vs. PHI (2 IP, 5 R-ER)…was optioned to AAA on 9/16 and recalled 9/26 for final Texas series of year...Made his MLB debut on 7/31/25 at SEA, becoming the fourth player and first pitcher to debut for Texas in 2025 (prev. Blaine Crim, Alejandro Osuna, Cody Freeman)… became the first Venezuelan-born pitcher to debut for TEX since Ricardo Rodriguez on 8/14/17 vs. DET…entered in the seventh inning of a 6-0 Rangers deficit and retired six of his seven batters faced over 2 SHO IP (1 H, 0 BB, 3 SO, 20 pitches/14 strikes)… struck out the first MLB batter he faced, catching Julio Rodríguez looking at a 1-2 fastball on the outside corner (97.2 mph)...Had a 3.76 ERA (17 ER/40.2 IP) and went 2-for-5 in save opportunities across 36 G with Round Rock in 2025, including 12-game scoreless run from 4/26-6/4 (12.2 IP)…the scoreless streak signaled the T3rd-longest run (by games) in the PCL last season…on the streak, allowed just five hits, three BB and three HBP while striking out 15, and posting a 0.63 WHIP figure with a .116 (5-for-43) opp. BA…ranked among PCL relievers (min. 40.0 IP) in opponents OPS (fourth, .662), SLG (sixth, .340), BA (sixth, .218).
2024
Turned in a standout campaign as a bullpen workhorse during his first year with Double-A Arkansas, which claimed the 2024 Texas League Championship…Curvelo established single-season career marks in games (49) and innings pitched (66.2), going 4-0 with a 2.57 ERA (19 ER/66.2 IP) and a Texas League-best 14 holds…notched 78 strikeouts to just 18 walks, ranking 8th-best in the Texas League with a 4.33 K/BB ratio…was named Mariners Minor League Pitcher of the Month for August, yielding just one run in 11.1 innings (0.79 ERA) while converting two save opportunities in 11 appearances during the month… his 49 appearances ranked second in the Texas League and his 0.86 WHIP was third-best…elected free agency on 11/4 and was signed by the Rangers to a Major League contract on 11/13… pitched in one game for Leones Del Caracas of the Venezuelan Winter League following the season.
2023
Spent the entire season with Everett (A+), pitching in 41 games (all relief) and matching his 2022 output with 52.1 innings pitched…went 3-1 with a 3.78 ERA (22 ER/52.1 IP), 60 strikeouts and four holds, ranking among AquaSox relievers in innings (1st), games (T1st), and strikeouts (T2nd)…owned a 4.40 ERA (14 ER/28.2 IP) through his first 23 appearances before closing the year with a 3.04 ERA (8 ER/23.2 IP) in his final 18 games.
2022
Appeared in 37 games (one start) for Everett…fanned 57 batters in 52.1 innings (9.80 SO/9) with a 4.82 ERA (28 ER/52.1 IP) and a .234 BAA (45-192)…fired 2.0 shutout innings in his lone start of the year on 9/6 vs. HIL, just his fourth professional start…also pitched in four games for Lara of the Venezuelan Winter League following the season.
2021
Ranked eighth in the California League with 13.01 SO/9 (80 SO/55.1 IP), going 5-1 with a 3.58 ERA and six saves across 37 games (all relief) for Modesto (A)…made six relief appearances for Peoria in the Arizona Fall League, striking out 15 in 12.2 innings.
