The Miami Marlins have made a key move ahead of the 2024 trade deadline, sending A.J. Puk to the Arizona Diamondbacks in exchange for infield prospect Deyvison de los Santos. Puk, who was once a top prospect with the Oakland Athletics, has transitioned to a reliable middle reliever since his debut in 2019. He has excelled this season with a 1.32 ERA and two saves for the Diamondbacks, though he is currently sidelined due to a flexor strain in his elbow. Despite the injury, the team remains optimistic about his recovery, believing he won't need surgery. In the meantime, Justin Martinez is expected to step into the closer role while Puk is out. Martinez boasts an impressive 0.90 ERA this season, demonstrating his potential as a strong replacement.

Devin Williams, the New York Yankees' new closer, entered the 2025 season as a highly valued fantasy asset thanks to his 1.83 career ERA and elite strikeout rate. After a stellar performance late last season with the Milwaukee Brewers, expectations were high for his role in New York. However, just weeks into the season, Williams has found himself among the most dropped closers on ESPN leagues following a series of inconsistent outings. A particularly troubling game against the Tampa Bay Rays saw him blow a four-run lead, raising concerns despite an underlying .423 BABIP indicating he’s been unlucky. Fantasy managers are urged to stay the course, as his performance should normalize.

Meanwhile, other closers like Jeff Hoffman of the Toronto Blue Jays and Kyle Finnegan of the Washington Nationals have seen their stock rise, with Hoffman perfect in save opportunities and Finnegan accumulating saves despite mediocre strikeout rates. Justin Martinez of the Arizona Diamondbacks is set to benefit from an increased role following the injury of A.J. Puk, while Jose Alvarado of the Phillies has stepped up as a reliable closer. Conversely, Baltimore's Felix Bautista is struggling and may need time to regain his pre-surgery form, prompting patience from fantasy owners.

In the evolving landscape of MLB bullpens, Justin Martinez has emerged as a strong candidate for saves with the Arizona Diamondbacks, especially in the wake of A.J. Puk's injury. However, Martinez's recent fatigue raises questions about his durability. Meanwhile, the Boston Red Sox's Aroldis Chapman remains in the driver's seat for saves even as high-leverage scenarios challenge his availability.

In Chicago, Ryan Pressly’s grip on the closer role appears secure despite recent struggles from his teammate Porter Hodge. Meanwhile, the White Sox remain a team to avoid for saves, having yet to record one this season. The Cincinnati Reds’ closer situation is murky with Emilio Pagán competing against Alexis Díaz, who has had setbacks since returning from the IL, giving Pagán an edge.

For the Cleveland Guardians, Emmanuel Clase’s struggles signal potential buy-low opportunities, while Tommy Kahnle continues to dominate the ninth inning for the Detroit Tigers despite recent heavy usage. Lastly, Devin Williams’ recent performance with the New York Yankees raises concerns, making him a player worth monitoring closely in fantasy leagues.

Five players from the National League West are currently undervalued in mid-to-late rounds of fantasy baseball drafts, offering significant potential for managers looking to bolster their rosters.

Michael Conforto, now with the Los Angeles Dodgers, presents a compelling case. After a strong showing with the San Francisco Giants, his metrics indicate he could thrive in a more favorable home environment. Meanwhile, Nick Pivetta, recently signed by the San Diego Padres, has solid strikeout rates and could see his performance improve with a shift to Petco Park.

Justin Martinez is the new closer for the Arizona Diamondbacks and has shown promising stats, including a high strikeout rate, suggesting he is a viable option for saves. Jung Hoo Lee is another name to watch; despite an injury-shortened debut, his contact metrics point to a potential breakout at a low ADP. Lastly, Michael Toglia of the Colorado Rockies has displayed elite barrel rates and power potential, making him a valuable late-round pick.

Corbin Burnes may not make his debut as the Opening Day starter for the Arizona Diamondbacks, potentially pushing his first appearance until the team's road game against the New York Yankees. After his recent outing, Burnes confirmed he will have another spring training outing, which may set him up for a start on April 1. This could mean he would have an extra day of rest, but it's unclear how this will impact his regular-season schedule. Manager Torey Lovullo hinted at adjustments in the pitching rotation to accommodate Burnes' schedule.

The Diamondbacks also announced a five-year contract extension for right-hander Justin Martinez, valued at $18 million, with conditional options based on his injury history. With the team expected to finalize their roster soon, key decisions loom regarding the fifth starter and bullpen positions, with names like Brandon Pfaadt and Ryne Nelson in contention.