2 Mariners fans should miss, 2 they shouldn't

The front office of any baseball team is constantly shifting players around. No one is safe from sudden trades and even marquee players have been sent packing for some reason or another. As a team who has done their fair share of moving players around in the past few years, let's take a look at a couple of players who went on to do great things after leaving Seattle and a couple of players who the team was right to let go.

Fans Should Miss - Paul Sewald

A bit of a late bloomer, Sewald was drafted by the Mets and wasn't called up the major leagues until the age of 27. After his first four years, he had accumulated a 5.50 ERA over 147 ⅓ innings and was non-tendered. After signing a minor league contract with the Mariners, he hit an incredible stride, improving in nearly every aspect. Across his 171 ⅔ innings with the organization, he posted a 2.88 ERA, 0.93 WHIP, and a 12.4 K/9, incredible numbers for any reliever.

Part of the improvement was simplifying his arsenal down to two pitches and really dialing in on his four-seam fastball. While his velocity on the pitch has always been below-average (it typically sits in the low-90s), he learned to master his wonky arm slot and VAA, or vertical approach angle. FanGraphs published an extremely detailed, nerdy article about his evolution in 2021 that might be worth a read if you're trying to avoid doing work or spending time with your family. Don't get me wrong though, his sweeper is also a fun little weapon for batters to face.

In a stunning move that many saw as a sell at the trade deadline, he was sent to the Diamondbacks in exchange for Josh Rojas, Ryan Bliss, and Dominic Canzone. He didn't do much in Arizona. All he did was accumulate 13 regular season saves, pitch eight scoreless innings in the NLWC, NLDS and NLCS, and help lead Arizona to the World Series.

With the Mariners within striking distance of the AL Wild Card spot and AL West division, who knows what could've happened if he had stuck around.

Fans Should Miss - Erik Swanson

After struggling in his first two seasons at the major leagues, Swanson finally start to put things together in 2021 where he posted a 3.31 ERA and 1.08 WHIP over 35 ⅓ innings. He got even better in 2022, improving to an astounding 1.68 ERA and 0.91 WHIP over 53 ⅔ innings, reducing the hard contact on his four-seam fastball by 9.4% and increasing the strikeout rate on his splitter by 9.9%. Along with Paul Sewald, Andres Munoz, and Penn Murfee, the Mariners had one of the most dangerous bullpens in 2022, a big reason why they were able to take the Houston Astros to an 18-inning game during the ALDS.

In an effort to bolster their lineup at the cost of pitching, the Mariners included Erik Swanson as the main component of a deal to bring Teoscar Hernandez to Seattle prior to the 2023 season. He took a slight step back, posting a 2.97 ERA and 1.10 WHIP over 66 ⅔ innings but was still immensely effective, doing the bulk of his work in the seventh and eighth innings. He struggled quite a bit in the ninth inning, with opposing batters averaging a whopping 1.140 OPS against him across 11 innings, but I guess that's why the Blue Jays have Jordan Romano.

Swanson's role as a late inning reliever was largely replaced by Justin Topa who was almost as effective but with him now gone too, the Mariners will have to depend on their ptiching development to produce the next crop of elite bullpen arms.

Fans Shouldn't Miss - Kyle Lewis

Following a glimmering college career that culminated in winning the Golden Spikes award, Lewis was taken 11th overall in the 2016 draft by Seatltle. He spent a few years in the minors before briefly being called up in 2019 and playing his first full season in 2020. His slash line of .262/.364/.437 was enough to win him the AL Rookie of the Year, the first Mariner to do so since a relatively unknown player by the name of Ichiro Suzuki in 2001.

Unfortunately for Lewis, things quickly began to go downhill. He had a decent start to 2021, coming up with a respectable .726 OPS and 104 OPS+ before suffering a meniscus tear in June and subsequently missing the remainder of the season. After a concussion and further issues with his knee, he spent the majority of 2022 in AAA and was finally traded to the Arizona Diamondbacks for Cooper Hummel. After the 2023 season, he was non-tendered by the Diamondbacks.

Because so much of his career has been affected by injuries since his breakout 2020 season it's hard to say if he can still reach the potential scouts saw in him as an amateur. In the 263 major league plate appearances he's had since winning Rookie of the Year, his OPS is a measly .623 with an OPS+ of 75. He raked in AAA with the Reno Aces, slashing .371/.457/.641 across his 293 plate appearances but like Jarred Kelenic, he's got some work to do before carrying that success to the majors.

With the huge turnover this offseason they'll be new fan favorites and others not so much.