In 2025, the Seattle Mariners won the AL West for the first time in 24 years and are poised to make the postseason for a second-straight season, the first time they’ve done so since 2000 and 2001. Their goal is to do a little more than just win the division and make the fall classic in 2026. Their goal is to now make their first World Series appearance in franchise history. They were one game away from doing so last year after a crushing defeat in seven games to the Toronto Blue Jays in the ALCS.
With their aspirations so high, the Mariners expect to make an even bigger leap in 2026, improving upon their 90-72 record from a year ago. At Fanduel, their over/under projection is set at 90.5 wins, making for a compelling case for them to hit the OVER for the upcoming season.
Why the Mariners Will Hit the OVER in 2026
Best Rotation in Baseball
One through five, I believe that the Mariners have the best rotation in baseball. It consists of, in no particular order, Bryan Woo, Logan Gilbert, George Kirby, Luis Castillo, and Bryce Miller. This rotation boasts a mix of heat, control, command, efficiency and movement.
Gilbert has been tabbed as Seattle’s Opening Day starter for the second consecutive season. In each of the last four seasons, he’s had ERAs of 3.20, 3.73, 3.23 and 3.44. He made his first All-Star game in 2024 and had a career-high strikeout total of 220, finishing sixth in the Cy Young voting. Gilbert started the season off strong in 2025 but was ruled out for over a month with a right elbow flexor strain. He struggled after he came back and didn’t get back to his normal self until late August, then he reminded everyone why he was an All-Star in 2024. Gilbert owns the strike zone with his command and efficiency.
Woo is another one who is efficient and has great command. He finished with the 11th-best ERA in baseball in 2025, 2.94, with 198 strikeouts in 30 starts. His impressive performance earned him a trip to the All-Star game and a fifth-place finish in the Cy Young voting. This was after collecting a 2.89 ERA over 22 starts in 2024. Woo also suffered an injury late last season that made him miss not only the rest of the regular campaign but the ALDS. He did return in the ALCS, but in relief. When at full strength, he is the ace of this staff.
Kirby has regressed, but he has the tools to bounce back at just 28 years old. In 2023 he had his best season yet, finishing with a career-best ERA of 3.35. He finished eighth in the Cy Young voting. The following year, he had an ERA of 3.53 and had a career-best 179 strikeouts. 2025 didn’t go so well though, having an ERA of 4.21. He also dealt with injuries last season, starting the year on the IL with shoulder inflammation. Kirby might be a back end of the rotation option but he still is one of the best strike throwers in the league with his command.
Castillo, on the other hand, is still performing like a top-end of the rotation talent. He’s had one season where his ERA was over 4.00 and that was all the way back in 2018. Castillo is as consistent as it gets. In 32 starts in 2025, he collected an ERA of 3.54 with 162 strikeouts. He also recently made the All-Star team in 2023. And don’t forget about Miller, who in 2024, had an ERA of 2.94 in 31 starts. Like the others, he dealt with injury in 2025 in what was a rough year and could very well miss some time to open up the 2026 season.
The theme of all of this is that the Mariners have the talent and depth one through five to match up against anyone in the sport, but health is the main issue. IF Seattle can stay healthy and get the best out of these guys, the rotation will be the best in Major League Baseball.
The Trade For Brendan Donovan
The Mariners had one of the best offseasons in baseball and that was due to the trade of utility man Brendan Donovan. In one of the best moves of the winter, the Mariners solidified themselves as a contender in the American League. Donovan can just do just about anything you can ask out of a baseball player. He has hit at the plate and can play around the diamond defensively, having a slash line of .282/.361/.422 and an OPS of .772 in his four seasons with the St. Louis Cardinals, while also winning a utility Gold Glove in 2022. His versatility is very valuable in today’s game and is what you want on a contender.Â
Adding Donovan to the team also means that they added yet another All-Star, as he made the mid-summer classic with the Cardinals in 2025. He might not have the name value of some of these other players but he balances out this lineup and makes the Mariners an even better defensive team than they already were.
Cal Raleigh and Julio Rodriguez
Adding a guy like Donovan to a team that features Cal Raleigh and Julio Rodriguez makes this team even better. Both players were the driving force of Seattle’s run last season and have the potential to be yet again for what could be a special year for the Mariners.
Raleigh has improved his numbers in each of the last four seasons. He hit 27 home runs with 63 RBI in 2022, which increased to 30 home runs and 75 RBI in 2023. His numbers increased yet again in 2024 when he hit 34 home runs with 100 RBI before having the best offensive year of any catcher in the history of the game last season when he hit a whopping 60 home runs with 125 RBI, earning him AL MVP runner-up. While Raleigh might not quite repeat what he did last season offensively, he is still the best catcher in baseball and one of the best hitters in the game. He will put up numbers.
When it comes to Rodriguez, he has consistently been their best player for years now. He’s made three All-Star games in four years and finished 7th, 4th, and 6th in AL MVP voting. Last season, Rodriguez hit 32 home runs with 95 RBI and stole 30 bases. He had the best WAR of his career at 6.8.
Safe to say that the Mariners will be relying on these two to lead what is a stacked lineup heading into 2026.
Seattle Won 90 Games Last Season
The Mariners have won exactly 90 Games in three of the last five seasons, including in 2025. They were also one game away from making their first-ever World Series appearance in franchise history. They have the motivation to have an even better 2026 and bring home their first championship.
Since they won 90 games last season and had a positive offseason, they would just need to improve by one victory to hit the over on their projected 90.5 win total in 2026, and they have a good chance of doing so.
Main Image: Dan Hamilton-Imagn Images
