5 players you forgot were on the Mariners (and wish they could have back)

For much of the late 2010s and into the early 2020s, Seattle Mariners fans could scan MLB rosters and spot a frustrating trend: countless former Mariners thriving somewhere else. It became almost comical how frequently talent slipped away, only to excel on another team.

However, in recent years, the Mariners' front office has reversed course, shifting its focus toward developing homegrown talent and fostering success within Seattle, rather than constantly shipping players out for marginal returns.

Yet, even with that change in philosophy, there’s no denying that several former Mariners still have the talent and experience to make an impact in Seattle today, especially with the club squarely in its championship window. Here’s a look at some of the biggest names Seattle might wish they still had.

Carlos Santana

One of the more recent and perhaps more painful departures was Carlos Santana. While Justin Turner could also fit this category, Santana’s decision stings a bit more. The Mariners made it clear they wanted him back, but Santana opted for less money to return to Cleveland.

It was a sentimental choice, as Santana told Paul Hoynes of Cleveland.com: “There were plenty of other offers. But Cleveland is my home. My family and I made the decision to come here.”

Statistically, Santana’s 2023 season with Seattle wasn’t impressive (.192/.293/.400, 15 HR, 39 RBI), but his leadership in the clubhouse was invaluable. His contract negotiations weren’t just about on-field performance, but also about maintaining his presence as a mentor. Seattle could still use a veteran presence like Santana, especially as they try to navigate the pressure of a playoff push.

Tyler O’Neill

The Tyler O’Neill trade remains a complicated one. In 2017, Seattle sent the highly touted outfield prospect to the St. Louis Cardinals in exchange for Marco Gonzales, a much-needed, MLB-ready arm. Gonzales became a mainstay in the Mariners' rotation for six seasons, peaking between 2019 and 2021 before injuries and declining performance led to his trade to the Atlanta Braves alongside Jarred Kelenic before the 2024 season.

While Gonzales’ contributions were meaningful, O’Neill has battled injuries throughout his career but has shined when healthy. He won Gold Gloves in 2020 and 2021. And in the latter season, he placed eighth in the NL MVP voting, finishing with 34 homers and driving in 80 runs while slashing .286/.352/.560 with a 148 OPS+.

More recently, O’Neill found a similar gear with the Boston Red Sox in 2024, hitting 31 home runs with a 132 OPS+ before landing with the Baltimore Orioles for the upcoming season.

Seattle’s outfield is relatively set, but O’Neill would be an ideal addition, bringing elite defense and serious pop. More importantly, he could have been a crucial piece bridging the gap before Julio Rodríguez's arrival in 2022, potentially altering the trajectory of the team’s offense during their early playoff pushes.

Kendall Graveman

Few trades sparked more outrage among players and fans than the 2021 deadline deal that sent Kendall Graveman to the Houston Astros.

At the time, the Mariners were heating up for a postseason push and Graveman was lights-out, boasting a 4-0 record with a 0.82 ERA and 10 saves. But instead of keeping him, Seattle sent Graveman and Rafael Montero (who later became a key piece in Houston’s bullpen) to their division rival in exchange for infielder Abraham Toro and reliever Joe Smith.

The Mariners' clubhouse was livid, feeling the front office had pulled the rug out from underneath them. That frustration still echoes into 2025 as Seattle struggles to fully solidify its bullpen. When Graveman hit free agency this past offseason, many expected the Mariners to right a past wrong. Instead, he signed with the Arizona Diamondbacks.

Graveman did miss all of 2024 after having shoulder surgery, and has since had a setback with back tightness. Yet given the current uncertainty surrounding Seattle’s relief corps, having even the promise of a healthy Graveman would have been a significant asset.

Eugenio Suárez

Ironically, Arizona is also home to another beloved former Mariner: Eugenio Suárez. Though he's hard to forget, the slugger was shipped to the Diamondbacks during the 2023 offseason, leaving many fans questioning Seattle’s infield depth. With Jorge Polanco now shifting from second to third base — a move that remains a question mark — Suárez’s presence would certainly provide stability.

While his offensive profile isn’t the cleanest fit for the Mariners’ new hitting philosophy, Suárez has adapted well in Arizona. He posted a .256/.319/.469 slash line with 30 homers, 101 RBIs, and a 116 OPS+ last season. His power and leadership were critical during his time in Seattle, and given what the Mariners now understand about their home ballpark’s impact on offense, keeping Suárez might have been the smarter move.

Chris Taylor

No discussion of former Mariners thriving elsewhere would be complete without mentioning Chris Taylor. Drafted in the fifth round of the 2012 draft, Taylor was traded to the Dodgers in 2016 for pitcher Zach Lee — a move Mariners President of Baseball Operations Jerry Dipoto later admitted was “clearly the worst deal I’ve ever made.”

Lee never played a single MLB game after the trade, while Taylor developed into a versatile star in Los Angeles. He helped the Dodgers win two World Series titles, earned a 2021 All-Star nod, and became a fixture at the keystone. Even in his later years, he remains a reliable defender and a solid bat.

At the time of the trade, Taylor was blocked at second base by Robinson Canó. But with Seattle still searching for a viable solution at the position, it’s hard not to wonder what could have been had he stayed in the organization.

The Mariners have learned their lesson

The Mariners are in a position where they need several players to have bounce-back seasons, relying on internal talent to step up. Yet, looking at the prime production these former Mariners have provided elsewhere, it’s clear that there's still room for them in Seattle.

Mariners fans shouldn’t dwell too much on the past; after all, there is plenty to be excited about in 2025. But learning from these mistakes is crucial. The organization appears to have recognized the importance of timing, roster construction, and player retention if they look to capitalize on their championship window.

The ghosts of these former Mariners still haunt the team — but they should serve as lessons for ensuring that history doesn’t repeat itself.