Which Team in the AL West Has the Best Closer for 2025?

The American League West should be one of the more fascinating divisions in all of baseball in 2025.

The Houston Astros won the division for the fourth consecutive year in 2024, securing their seventh AL West title in the last eight seasons. But with Alex Bregman and Kyle Tucker no longer in the picture, the division is much more up for grabs than it has been in previous years. They remain the odds-on favorite to win the division, but teams are coming to dethrone them from the top of the standings.

The Texas Rangers head into 2025 as one of the biggest boom-or-bust teams in MLB. After winning the World Series in 2023, the Rangers came back down to earth last season and missed the playoffs after winning just 78 games. But better days are ahead for their offense, and with deGrom returning to the bump, they’re a team that could push for a division title and make some noise in the postseason.

The Seattle Mariners continue to bolster one of the strongest starting rotations in baseball. Though their offense underwhelmed in 2024, they’re expected to get back into postseason contention and fight to secure an AL West title this season — something they haven’t been able to accomplish since 2001.

With a division that’s expected to be so competitive near the top, a strong bullpen could be the difference-maker in how the standings shake out. A reliable bullpen is led by a lockdown closer, and some teams in the AL West have a more lethal ninth-inning option than others.

As we begin to preview the upcoming season, let’s take a look into each team in the AL West and determine which ball club has the best closer for 2025.

5. Chris Martin, Texas Rangers

2024 Stats: 45 G, 44.1 IP, 2/6 SV/SVO, 15 HLD, 3.45 ERA, 1.13 WHIP, 2.78 FIP, 10.15 K/9, 0.61 BB/9, 46.3% GB%

After spending his previous two seasons in Boston, Chris Martin signed with the Rangers this offseason to serve as the ball club’s closer for 2025.

Martin, 38, was quite successful with the Red Sox. Back in 2023, he was one of the best relievers in the sport, pitching to an ERA of 1.05, which was the best in MLB among qualified relievers.

While his results on the surface level weren’t as profound in 2024 (3.45 ERA), he was an effective setup option for Boston when he was on the mound.

For starters, his FIP of 2.78 and SIERA of 2.43 (10th-best SIERA in MLB among pitchers with at least 40 innings) suggest he had a better year than his ERA indicates.

Moreover, Martin’s command was second to none last season. He ended the year with a dazzling walk rate of just 1.7%, which was a career low, and he had the best BB/9 in MLB at 0.61 (min. 40 IP). While he doesn’t blow hitters away in the batter’s box, he managed to increase his strikeout rate over four percent in 2024 to 27.8%.

Outside of a splitter in which he throws 13.1% of the time, Martin manipulates three different types of fastballs to fill out the rest of his arsenal: a cutter (45.5%), four-seam (30.9%), and sinker (9.6%).

Now entering his age-39 season, Martin’s best days are behind him. Yet, he will have an immensely important role at the tail end of ballgames for Texas.

4. Kenley Jansen, Los Angeles Angels

2024 Stats: 54 G, 54.2 IP, 27/31 SV/SVO, 3.29 ERA, 1.06 WHIP, 3.00 FIP, 10.21 K/9, 3.29 BB/9, 30.6% GB%

Martin’s former teammate from a season ago, Kenley Jansen, slides in just ahead of him on this list.

We’re all aware of the experience Jansen brings to the table at this point in his career. Just three saves shy of 450 in his career, Jansen joined the Los Angeles Angels this offseason in an attempt to rack up as many saves as possible to remain on a Hall of Fame track to Cooperstown.

While he’s obviously no longer in the prime of his career, Jansen has put together some solid years as a reliever for several different ball clubs recently.

Since posting a 2.22 ERA in 69 innings with the Dodgers back in 2021, Jansen is pitching to a 3.42 ERA while averaging 32 saves a year across his three most recent seasons with Atlanta (2022) and Boston (2023-’24). He even earned an All-Star bid with the Red Sox in 2023.

Last season, Jansen pitched to a 3.29 ERA to go with a FIP of 3.00 in 54.2 innings as Boston’s closer. He recorded 27 saves in 31 opportunities, and opposing hitters had a batting average of just .193 against him.

Jansen’s arsenal hasn’t changed over the years. In 2024, his cutter usage of 84.9% was the highest since his 2017 season. It still generated whiffs at a 28.2% rate and had a batting average against of .215, which were both improvements from 2023.

He threw his slider 7.7% of the time last season and did not surrender a single hit off of the pitch. Likewise, his sinker usage has tailed off over the years, peaking at 28.7% in 2020 and dropping to 7.4% last season.

Like Martin, Jansen’s upside is limited at this point in his career, but you know what you’re going to get from him given his recent track record. He can be penciled in for a mid-3.00s ERA and will flirt with 25 or more saves, depending on opportunities.

He’s never ended with a K/9 below 10.00 throughout his 15-year career, so it’s safe to assume that trend will continue in 2025.

For the Angels, Jansen will serve as an important mentor for flamethrower Ben Joyce, who is the organization’s next young closer waiting in the wings. Expected to take over as the primary closer earlier in the offseason, Joyce will now function as the hard-throwing setup option to Jansen.

Joyce will turn heads with his ability to hit 105 mph on the radar gun, and Jansen will get fans to tune in late in ball games to see a possible future Hall of Famer add to his closer resume.

Jansen gets the nod over Martin thanks to his career accolades and pedigree as a closer, but his lack of ceiling at this point in his career keeps him firmly behind the other three names ahead of him on this list.

3. Andrés Muñoz, Seattle Mariners

2024 Stats: 60 G, 59.1 IP, 22/27 SV/SVO, 6 HLD, 2.12 ERA, 0.96 WHIP, 3.35 FIP, 11.68 K/9, 3.94 BB/9, 52.3% GB%

Since 2022, Muñoz has thrived at the tail end of games for Seattle. Over his previous three seasons, Muñoz is 14th among qualified relievers in ERA (2.49) and fWAR (3.7) while also ranking 11th in FIP (2.68).

Earning his first All-Star bid in 2024, Muñoz had a career year on the mound. In 60 appearances (59.1 IP), he ended with a career-low ERA of 2.12, and he featured some of the best strikeout material in the sport.

Muñoz blows hitters away with a four-seamer that sits 98.4 mph and a sinker that averages 97.5 mph. He has a devastating slider to play off those two fastballs, as the pitch generated whiffs nearly half of the time last season.

As a whole, Muñoz had one of the best swing-and-miss rates in MLB at 39.8%, and that led to a strikeout rate of 33.2% that was in the top five percent of baseball, according to Baseball Savant. Even when opposing hitters made contact with his pitches, they hardly did any damage against him.

Muñoz generated a groundball rate of 54%, which was in the 92nd percentile. What’s more, opposing batters hit just .153 against Muñoz last season, which was the fifth-best mark in MLB among qualified relievers.

His expected numbers followed suit thanks to his ability to limit hard contact, finishing the year in the top 10 percent in xBA (.178), xSLG (.308), and xWOBA (.267).

All in all, it was quite a season for the 26-year-old, and he’s established himself as the alpha in Seattle’s bullpen.

2. Josh Hader, Houston Astros

2024 Stats: 71 G, 71 IP, 34/38 SV/SVO, 3.80 ERA, 0.96 WHIP, 3.50 FIP, 13.31 K/9, 3.17 BB/9, 30.3% GB%

Josh Hader’s first season in Houston was a bumpy one. Specifically, consistency on the mound was an issue for the southpaw.

His 3.80 ERA sticks out when compared to his previous seasons, but his production often fluctuated from month to month. For example, in the month of April, he posted an ERA of 7.45. He then followed that up with an ERA of 1.35 in the month of May. That was the general theme of his 2024 campaign.

When looking at what went wrong, opposing hitters made much more damaging contact against him last season. His hard-hit rate jumped over 10%, and his barrel rate went from 4.4% in 2023 to 10.2% in 2024.

His leap in homers surrendered supports those trends. Hader allowed 12 homers last season and ended the year with a HR/9 of 1.52; Each of those marks were his highest since 2019.

With that being said, it’s important to acknowledge that he was still one of the more impressive strikeout artists in baseball in 2024.

In his age-30 season, Hader increased his strikeout rate by a full percent to 37.8%, which was the third-best mark in MLB among qualified relievers. While his walk rate of 9% was still below average, he managed to cut the rate by four percent from his previous season.

He was inducing chase at one of the highest rates of his career (33.4%), and no pitcher in MLB (min. 50 IP) had a higher whiff rate than Hader last season (40.5%), per Baseball Savant.

It was a similar story in terms of pitches within the strike zone, as he had the second-best in-zone whiff rate in baseball at 32.7% (min. 50 IP).

Opposing hitters posted a batting average of just .171 against Hader last season, and he ended the year with his lowest WHIP (0.96) since 2021 as well. Moreover, he finished the year with 34 saves, marking the fourth consecutive year in which he’s recorded 33 or more saves.

Sure, perhaps he’s no longer in the conversation for being the best closer in MLB like he once was when he was with Milwaukee, but he still has the ability to be a lights-out closer when in control on the mound.

Houston’s bullpen is top-heavy, but even without Ryan Pressly, they still have several impressive names to bridge to Hader in the ninth.

Tayler Scott, Bryan King, and Kaleb Ort all ended the year with an ERA south of 2.60 last season. Whether or not they can continue that level of success is yet to be seen, but it was certainly encouraging to see nonetheless.

Add in Bryan Abreu, who has the talent to bounce back in a big way in 2025, and the Astros have some strong options to pair with Hader capping off games.

His run prevention may have taken step back last season, but Hader showed that he still has the ability to get the big strikeout when needed. He heads into 2025 as the second-best closer in the AL West.

1. Mason Miller, Athletics

2024 Stats: 55 G, 65 IP, 28/31 SV/SVO, 2.49 ERA, 0.88 WHIP, 2.18 FIP, 14.40 K/9, 2.91 BB/9, 40.7% GB%

The best closer in the AL West for 2025 is none other than Mason Miller. Bursting onto the scene with the Athletics, Miller quickly established himself as one of the top relievers in all of baseball heading into 2025.

Miller ended his first full season as a big league closer with an ERA of 2.49, but his peripherals suggest he was far more dominant than his ERA indicates.

Miller has the best xERA and SIERA in MLB among qualified relievers at 1.77 and 1.91, respectively. Likewise, he had the fifth-best FIP at 2.18, and his xFIP was the single best among relievers at 2.21.

Miller’s dominance stems from his sensational swing-and-miss material. Standing at 6-foot-5, Miller launches off the mound with a four-seam fastball that averages triple digits to go with a slider that generated a wOBA of just .170 and a whiff rate near 50% last season.

Overall, Miller’s chase rate of 37.4% was in the 99th percentile, and his whiff rate of 40.1% was the second-best mark in MLB (min. 50 IP). In turn, it’s no surprise to see that he led MLB relievers in K/9 (14.40), strikeout rate (41.8%), and K-BB% (33.3%).

Opposing hitters hardly did any damage against him as well. He had a barrel rate under six percent, and his hard-hit rate of 32.5% was in the top 10% of baseball. In turn, Miller was in the 100th percentile in xERA (1.77), xBA (.150), xSLG (.225), and xWOBA (.206).

Miller was arguably the most dominant reliever in MLB last season not named Emmanuel Clase, and he’s only scratching the surface of what he’s capable of heading into his age-26 season.

As a whole, the A’s bullpen isn’t expected to be any good in 2025. José Leclerc can be a serviceable setup man with his new ball club, and they have some intriguing relievers worth monitoring in 2025. But Miller will be the long bright spot among the A’s pitching staff.

Moving forward, it will be fascinating to see how the Athletics handle Miller’s future.

He was one of the hottest names mentioned around the trade deadline this past season, and it wouldn’t be a surprise to anyone to see the A’s cash in on his value as he’s the brightest young reliever in MLB.

At the same time, after signing Brent Rooker to an extension earlier this offseason and more recently locking up Lawrence Butler to a guaranteed contract, perhaps Miller is next in line to receive a long-term deal to remain with the Athletics.

In the meantime, Miller heads into 2025 as not only the best closer in the AL West, but one of the best closers in all of MLB.