ZiPS most improved player predictions have Mariners set up for 2025 success

Seattle Mariners fans are no strangers to disappointment. Following a lackluster 2024 season, uncertainty has continued to loom over the franchise. However, a recent analysis by MLB writer Thomas Harrigan offers a reason for optimism.

Utilizing the advanced statistical model ZiPS (Zymborski Projection System), Harrigan and his team conducted an extensive study to forecast player performance for the 2025 season. By analyzing every MLB player who logged at least 450 plate appearances or played 75 games in 2024, they compared actual WAR (Wins Above Replacement) to projected WAR for the upcoming season.

The results? A glimmer of hope for Seattle.

Two Mariners landed among the top 10 projected biggest risers in WAR, signaling potential breakout seasons that could reshape the team’s trajectory. None other than franchise star Julio Rodríguez and the recently re-signed Jorge Polanco are both forecasted to make significant leaps in 2025. Let’s break down why these projections could be a game-changer for Seattle.

Since his explosive MLB debut in 2022, Julio Rodríguez has been the heart and soul of the Mariners’ lineup. His power, speed, and defensive excellence were instrumental in ending the team’s long-standing postseason drought. However, by his own high standards, 2024 was a step backward.

While not a bad season, Rodríguez’s numbers weren’t at the superstar level fans had come to expect. Across his first two seasons, he posted a .834 OPS and a 137 wRC+, but in 2024 those numbers dipped to a .734 OPS and a 116 wRC+, with a WAR of just 3.8.

ZiPS projects a strong rebound, forecasting a 2.3 WAR increase, bringing him up to 6.1 in 2025. That ties him for third on MLB’s projected list of most improved players, behind only Braves outfielder Michael Harris and Rays utilityman Christopher Morel.

A Rodríguez bounce-back season shouldn’t surprise anyone. His struggles in 2024 were largely due to a nagging ankle injury and a five-week power outage, where he failed to hit a single home run. But when healthy, Rodríguez flashed his superstar form.

His September 2024 numbers tell the real story. In just 26 games, he slashed .328, racked up 39 hits, 7 home runs, 22 RBI, and scored 24 runs. A fully healthy, dominant Rodríguez would not only anchor the lineup but also elevate the entire team. If the Mariners get this version in 2025, they could be on the verge of a revitalization reminiscent of their magical 2022 campaign.

Can Jorge Polanco bounce back and strengthen the Mariners' infield?

One of the biggest surprises on the list, ranking 10th overall, is Jorge Polanco. His return to Seattle was met with mixed reactions, largely due to his disastrous 2024 campaign, where he posted career-worst numbers across nearly every offensive category. However, as details emerged, it became clear that Polanco was playing through significant pain for much of the season, severely impacting his production.

Typically a steady, veteran bat, Polanco saw his strikeout rate spike to 29.2% while his offensive output plummeted. As a result, his WAR cratered to just 0.3. Now, healthy once again, Polanco is a prime candidate for a bounce-back year. The ZiPS projection system forecasts a 1.3 WAR increase, bringing him up to 1.9 WAR in 2025.

Polanco’s move to third base carries major significance for the Mariners, addressing one of their big infield weaknesses from 2024. Last season, Seattle’s third basemen struggled offensively, collectively managing just a .212 batting average with a 99 wRC+, leaving a glaring hole in the lineup. Even after a down year, Polanco’s career wRC+ of 109 suggests that a return to even league-average production would be a clear improvement. With his experience, his presence at third base could provide much-needed stability and a boost to Seattle’s offense.

With Rodríguez poised for a resurgence and Polanco at full strength, the Mariners have two key pieces trending in the right direction. For a team looking to erase the sting of 2024, these projections suggest that Seattle might be closer to contention than many believe.