Top 10 Best Pitchers in the AL West for the 2026 MLB Season
This year's AL West is packed with pitching talent, so we attempted the impossible and ranked the best arms in the division.
| | 
If pitching wins championships, the American League West might already have a head start.
Loaded with aces, breakout candidates, and proven postseason arms, no division in baseball can match its depth on the mound. From Seattle’s homegrown dominance to Houston’s consistency and Texas’s aggressive roster building, elite pitching defines the AL West entering 2026.
So, who are the ten best arms in the division?
Let’s count down the top 10 pitchers in the AL West, starting at No. 10 and working our way to the top spot.
Who Just Missed the Top 10?
Houston Astros – Josh Hader, Bryan Abreu, Cristian Javier
Hader remains one of the elite closers in Major League Baseball, but will unfortunately begin the year on the injured list with bicep tendinitis. The six-time All-Star had a 2.05 ERA in 52.2 innings while striking out 76 and collecting 28 saves last year. Entering his age-32 season, Hader has shown no signs of slowing down and could very well end up back on this list next season.
Since 2022, Abreu has posted a 2.30 ERA across 281.1 innings, racking up 396 strikeouts. He’s been nothing short of dominant in his role as the primary setup man for Hader, consistently overpowering hitters in high-leverage spots. After signing a one-year, $5.85 million deal for 2026 to avoid arbitration, Abreu is set to hit free agency in 2027. If his production holds, he won’t just be paid like an elite reliever, he’ll likely be closing games somewhere else.
This will be Javier’s first full season after undergoing Tommy John surgery in 2024. Before his injury, he had one of the best four-seam fastballs in the league, with 20 inches of induced vertical break, creating the “ride” effect. For Javier, it’s more about staying healthy over the course of a full season, but he has the talent and upside to be on the list.
Seattle Mariners – Matt Brash
In terms of pure stuff, few compare to Matt Brash. He possesses a slider that is a true outlier pitch, and he generates an immense amount of swing-and-miss. The talent is undeniable, but for Brash to crack the top 10, he has to show durability and more consistency around the plate.
10. Andrés Muñoz, Seattle Mariners
2025 Stats: 64 G, 62.1 IP, 38 SV, 1.73 ERA, 2.43 FIP, 1.03 WHIP, 11.98 K/9, 4.04 BB/9
Muñoz has firmly established himself in the top tier of relievers. Building off of his breakout season in 2024, Munoz racked up 38 saves in 2025, good for the third most in baseball.
Coming off back-to-back All-Star selections, Muñoz shows no signs of slowing down. He generates whiffs (36.5%), chase (31.3%), and strikeouts (32.7%) at one of the highest rates in the league. Expect Muñoz to continue his dominant stretch and push for a 40-save season.
9. Tatsuya Imai, Houston Astros
2025 NPB Stats: 24 GS, 163.2 IP, 1.92 ERA, 0.89 WHIP, 3.35 FIP, 9.79 K/9, 2.47 BB/9
Imai was one of the more coveted players this free agency cycle and signed with the Houston Astros in January. In nine years over in the KBO, he posted a 66-49 record with a 3.07 ERA, 1,045 strikeouts, and a 1.27 WHIP across 1,077.2 innings pitched.
Imai’s arsenal consists of a four-seam fastball, slider, changeup, splitter, “vulcan” change, and a curveball. His fastball sits in the mid-to-upper 90s, while his slider and changeup sit in the mid-80s.
What makes Imai unique is his arm slot. He releases the ball at a low, side arm release point, giving both his fastball and changeup tons of horizontal movement while giving his slider more vertical break.
He immediately slots at the top of the rotation after the departure of Framber Valdez and is one of the favorites for the 2026 AL Rookie of the Year.
8. Luis Castillo, Seattle Mariners
2025 Stats: 30 GS, 159.2 IP, 4.17 ERA, 1.35 WHIP, 3.74 FIP, 10.43 K/9, 3.61 BB/9
Castillo has been as durable as they come, making at least 25 starts in every season since 2021.
While age is beginning to show in subtle ways, most notably a gradual dip in fastball velocity, he still commands one of the league’s most effective four-seamers. Castillo remains a reliable source of quality innings and continues to pitch in what is the best rotation in baseball.
7. MacKenzie Gore, Texas Rangers
2025 Stats: 25 GS, 131 IP, 3.44 ERA, 1.03 WHIP, 3.35 FIP, 11.89 K/9, 2.13 BB/9
It looked like a true breakout was underway for Gore. Over his first 19 starts, he posted a 3.02 ERA with a 2.96 FIP, flashing the frontline potential that’s long made him one of the game’s most exciting arms. But over his final 11 starts, he owned a 6.75 ERA.
The issue wasn’t his stuff, it was his command. Inconsistent strike-throwing led to too many blow-up outings in 2025. Still, the talent remains undeniable. Gore’s fastball, curveball, and slider combination ranks among the most electric in the league.
It all comes down to consistency. If Gore can limit the lapses and find the strike zone more reliably, the ceiling is still immense. Put it all together, and he won’t just climb this list; he’ll be firmly in the conversation with the best pitchers in baseball.
6. Nathan Eovaldi, Texas Rangers
2025 Stats: 22 GS, 130 IP, 1.73 ERA, 0.85 WHIP, 2.80 FIP, 8.93 K/9, 1.45 BB/9
Eovaldi was putting together a career year in his age-35 season, but couldn’t escape the injury bug. He missed time in May with triceps fatigue, suffered a rotator cuff strain in August, and ultimately underwent sports hernia surgery in October.
Hopefully, with those injuries behind him, Eovaldi should return to doing what he does best, dominating the bottom of the zone with a deep arsenal featuring his four-seamer, splitter, cutter, and curveball.
Living at the bottom of the zone allowed him to generate a 51.2% groundball rate and induce decent weak contact. His 4.2% walk rate places him in the 98th percentile, and he posted a decent strikeout rate of 26% (75th percentile).
If healthy, he remains one of the most reliable starters in the game and a key piece for the Rangers’ rotation.
5. George Kirby, Seattle Mariners
2025 Stats: 23 GS, 126 IP, 4.21 ERA, 1.19 WHIP, 3.37 FIP, 9.79 K/9, 2.07 BB/9
Kirby got off to a delayed start in 2025 due to right shoulder inflammation that sidelined him until late May.
Following his return, it was an up-and-down season. A noticeable drop in arm slot, nearly eight degrees, may have contributed to his struggles, particularly in limiting hard contact and generating swing-and-miss, both of which took a step back.
This ranking ultimately serves as a projection. Kirby still possesses Cy Young-caliber talent and proved his durability with back-to-back 190+ inning seasons in 2023 and 2024, each with a sub-3.60 ERA. With a clean bill of health entering the season, he’s well-positioned to bounce back and solidify his place among the game’s top arms.
4. Logan Gilbert, Seattle Mariners
2025 Stats: 25 GS, 131 IP, 3.44 ERA, 1.03 WHIP, 3.35 FIP, 11.89 K/9, 2.13 BB/9
Another member of the stacked Mariners rotation with Cy Young upside is Gilbert.
The towering right-hander is something of an outlier, generating 7.6 feet of extension, effectively releasing the ball more than a foot closer to the plate than the average pitcher. That trait helps him miss bats at an elite level, consistently ranking near the top of the league in both whiff (32.9%) and strikeout rate (32.3%).
At times, Gilbert struggled to command his four-seamer and slider, leaving them over the heart of the plate and giving up more hard contact than in years past. Even so, the talent and arsenal are undeniable. If he harnesses his command, Gilbert has all the tools to develop into a legitimate Cy Young contender in the near future.
3. Bryan Woo, Seattle Mariners
2025 Stats: 30 GS, 186 2/3 IP, 2.94 ERA, 0.93 WHIP, 3.47 FIP, 9.55 K/9, 1.74 BB/9
Woo stands as the top arm in the Mariners’ rotation. After offering a glimpse of his potential in 2024, he fully delivered in 2025.
Armed with some of the cleanest mechanics in baseball, Woo dominated behind his four-seam fastball. The pitch produced a 21 Run Value, tied for second among all four-seamers in the league. He displayed elite control, limiting walks to 4.9% rate (95th percentile) while striking batters out 27.1% of the time.
There isn’t much else Woo could have done last year to move up any higher on this list. It goes to show the talent there is in the AL West currently.
2. Hunter Brown, Houston Astros
2025 Stats: 31 GS, 185.1 IP, 2.43 ERA, 1.03 WHIP, 3.14 FIP, 10.00 K/9, 2.77 BB/9
Coming in at No. 2 is Brown, the Houston Astros’ ace, who was nothing short of brilliant last season.
An increased usage of his sinker and knuckle curve unlocked another level, helping Brown finish third in Cy Young voting and firmly establishing himself as one of the top starters in baseball.
His season was no fluke, either. His 3.14 xERA (85th), 86.1 mph average exit velocity (97th percentile), and 32.2% hard-hit rate (97th percentile) all point to a pitcher with sustainable success. The only knock on Brown is his walk rate of 7.8%, which is right around league average.
Regardless, he is to anchor the Astros rotation and overpower lineups for years to come.
1. Jacob deGrom, Texas Rangers
2025 Stats: 30 GS, 172 2/3 IP, 2.97 ERA, 0.92 WHIP, 3.64 FIP, 9.64 K/9, 1.93 BB/9
When deGrom is on the field, baseball is in a better place. After years of inconsistency due to injuries, we finally got a full season of deGrom, and he looked every bit as dominant as we remember.
When healthy, deGrom is simply one of the best pitchers in the game.
His four-seamer was once again among the best in the league, with opponents batting .189 against it. The slider was coming out of the hummer, sitting at 90 mph, generating a 39% whiff rate. He hasn’t lost a step.
The only thing that has ever held him back isn’t his talent, it’s his durability. As long as his body holds up, few pitchers in baseball can match the level of dominance he brings.
Become a Member of Just Baseball
Subscribe and upgrade to go ad-free!
* Save 25% by subscribing annually.
Written by
Ethan is an aspiring sports analyst who has a passion for all sports. He was a collegiate baseball player and is now finishing up his schooling…