Why the Mariners bullpen in 2026 could be electric after disastrous 2025 finish

The Seattle Mariners had their 2025 season come to an end sooner than the players and fans were hoping. Falling short in Game 7 of the American League Championship Series hurt the city of Seattle, and will haunt the franchise until they are able to break through and reach the World Series for the first time in franchise history. During their special playoff run, we saw the Mariners use their best pitchers in unique ways and if they find their way back to the playoffs in 2026, we could see an even more electric pitching staff due to two highly talented prospects.

The Mariners have built their team on a foundation of homegrown starting pitchers who have turned into a quality big league rotation. In 2024, the rotation performed at an elite level and was among the best in the league. In 2025, after a year of perfect health for those starters, nearly all of the Mariners' five main starters dealt with injuries. George Kirby began the season on the Injured List with a shoulder injury, Logan Gilbert missed time with an arm/elbow issue, Bryce Miller also had an elbow issue that caused multiple IL stints, and at the end of the season Bryan Woo had a pectoral injury.

The injury to Bryan Woo right at the tail end of the season really hurt. Until that point, he had been the healthiest and best performer on the staff. He went six innings in 25 straight starts and was incredibly solid all season long. Not being able to start him in the ALDS forced the Mariners to start Bryce Miller in Game 4 of that series instead of having him come out of the bullpen. That kept the Mariners from adding Miller to the pen as a multi-inning weapon.

The Mariners could make 2 huge additions to their 2026 bullpen

We saw the Mariners' starting pitchers struggle to go deep into games in the playoffs and ultimately did not have a start of longer than 6.0 innings. That put a lot of stress on the middle of the bullpen and on relievers like Eduard Bazardo, Gabe Speier, and Matt Brash specifically. Perhaps things would have gone differently if the Mariners had more quality arms to bridge the gap to Andrés Muñoz.

Looking ahead to 2026, the Mariners are not guaranteed another postseason run. But if they can get there, they could have two players who were not on the 2025 team to help strengthen the bridge from the starters to the back end of the bullpen. The Mariners have two high-end pitching prospects who should not be far away from the big leagues and could make an impact in 2026: switch-pitcher Jurrangelo Cijntje and this year's No. 3 overall pick, Kade Anderson.

Those two prospects could wind up on fast tracks to the big leagues. There is also now recent precedent for having pitchers move quickly through the minor leagues to help a team in a pennant chase. The Mariners saw firsthand how the Toronto Blue Jays used Trey Yesavage to help them get to a World Series after he pitched at every minor league level this season. The Mariners could take a similar approach with Anderson and Cijntje (who the Mariners chose to draft over Yesavage).

Anderson has not thrown a professional pitch for the Mariners yet. He had a dominant season at LSU where he pitched 119 innings and had 180 strikeouts to go along with a 3.18 ERA. To finish his season he also thew a complete game shutout in the College World Series to help his team win a title.

The Mariners would not have to move as fast with Cijntje as they would with Anderson, because we already saw Cijntje reach Double-A in 2025 and posted a sub-3.00 ERA in 7 starts. He threw just over 108 innings between High-A and Double-A, so he should be in line for a small bump in innings next year. His ability to throw with both arms could really be a weapon in the playoffs due to his ability to face any hitter with a platoon advantage every time.

Having these two talented and unique individuals is great, but how could they work in tandem with the current Mariners rotation to make an elite pitching staff in the postseason? If we assume that all five of the current starters — Logan Gilbert, Bryan Woo, George Kirby, Luis Castillo, and Bryce Miller — are all healthy going into the playoffs in 2026, adding Anderson and Cijntje gives the Mariners seven startable pitchers.

We saw this year in the playoffs that you really only need four starters with all the extra off days. The Mariners could go with Gilbert, Woo, Kirby, and Castillo as their four starters and then have Miller, Anderson, and Cijntje available to come out of the bullpen with the ability to cover multiple innings. If the Mariners were to only get four innings from their starter, they could go to one of those three other guys for the next three innings and then only need two innings from their high-leverage relievers.

That could be a real recipe for success and gives the Mariners an extra layer of options on a nightly basis out of the pen. Instead of strong lefties like Kerry Carpenter seeing Gabe Speier multiple days in a row, the Mariners could throw Anderson out there to shut him down, or they could have Cijntje pitch left-handed to him. Having a switch-pitcher also gives the Mariners the ability to use him out of the bullpen right-handed one day and left-handed the next.

All of the different possibilities that having two more pitchers who can throw multiple innings would give Mariners Manager Dan Wilson is exciting. Hopefully the Mariners are able to stay healthy and develop their prospects in 2026, so that they can push all their chips in the middle to go try to win it all.