Luis Curvelo

November 13: The Rangers made it official today, announced they signed Curvelo to a major league deal. Their 40-man roster count climbs to 37.

November 10: The Rangers are closing in on a deal with right-handed reliever Luis Curvelo, reports Jon Morosi of MLB Network. It will be a major league contract for the 24-year-old hurler.

Earlier this month, Morosi reported that Curvelo was “one of the most popular free agents” at the annual GM Meetings in San Antonio. To be clear, that doesn’t necessarily mean that teams preferred Curvelo to any of the top relievers on the market. More likely, it means they viewed him as a low-risk, high-reward target who could provide meaningful innings at a fraction of the price of a proven big league pitcher.

The Venezuela native signed with the Mariners as an international free agent in 2018 and worked his way up to Double-A Arkansas in 2024. Over 49 games (66 2/3 IP) this past season, he produced the best numbers of his career to date, pitching to a 2.57 ERA and 3.03 FIP. An unusually low 7.8% home run-to-fly ball ratio and an unsustainable .227 BABIP are signs that he’s due for some regression, but even so, it’s hard not to be impressed by his performance – especially his 30.6% strikeout rate.

Curvelo has been a full-time reliever since his age-18 season, which partially explains why he was never a highly-ranked prospect in Seattle’s system. However, Eric Longenhagen of FanGraphs liked what he saw enough to rank Curvelo as the no. 31 prospect in the Mariners organization this past July. Longenhagen was unconvinced by the righty’s fastball but had nothing but praise for his slider. For what it’s worth, Curvelo was even better from July onward, putting up a 1.86 ERA, a 2.44 FIP, and a 33.6% strikeout rate over his final 29 innings pitched.

As for why Seattle would let Curvelo walk after such a strong season? He was eligible for minor league free agency this offseason, and the Mariners would have had to add him to their 40-man roster to prevent him from leaving. Morosi suggests they simply didn’t have space on the 40-man, and evidently, they weren’t willing to make space either. The Rangers currently have four open spots on the 40-man, giving them plenty of room to add Curvelo to the mix. There’s a good chance he’ll begin the 2025 campaign at Triple-A Round Rock (he still has all of his minor league options remaining), but presumably, Texas is hoping he’ll play a role in the big league bullpen at some point next year.

By almost every metric, the Rangers’ bullpen was one of the worst in the league this past season. Collectively, Texas relievers ranked 26th in ERA, 23rd in SIERA, and 25th in FanGraphs WAR. To make matters worse, those poor numbers came in spite of phenomenal performances from veterans Kirby Yates and David Robertson, both of whom are now free agents. So are swingman José Ureña and Rangers bullpen mainstay José Leclerc. If this team is planning to get back into contention in 2025, and there’s no reason to think they aren’t, the bullpen is an obvious area for improvement. However, owner Ray Davis is reportedly hoping to get back under the $241MM luxury threshold, which means president of baseball operations Chris Young will have limited funds at his disposal. Thus, it makes perfect sense that Young would target the relatively inexpensive upside of Curvelo.