3 frustrating Mariners players who are getting harder to defend

Being a professional athlete is hard and baseball might be the hardest sport of them all. Over a 162-game season, an individual might go through several hot and cold streaks. It's on the fans to continue having their back in case the moral support ends up being the main difference maker.

Despite their recent success and closing the distance on the AL West-leading Texas Rangers, several Seattle Mariners players have continued to underperform their expectations.

These 3 Mariners are falling short of expectations and need to be better

J.P. Crawford

Every Mariners fan is waiting for 2023 Crawford to come back in some form. His offensive regression last year can easily be attributed to his struggles with various injuries, but we've yet to see the benefits of him being (supposedly) fully healthy in 2025.

He's slashing .231/.383/.262 over 83 plate appearances, which tells us two things. One, he's still got one of the best eyes in baseball with a 18.1 walk percentage. Two, the lack of pop is really holding him back from making the most out of his plate discipline.

Compared to other major league sluggers, Crawford has never been one to post jaw-dropping exit velocities. However, he was able to make the most out of what he had, squaring up the ball at an above-average rate in 2023. That rate has decreased steadily ever since and in 2025, he's only squaring the ball up more than seven percent of qualified hitters. This leaves most of his batted balls in the infield and he has yet to hit his first home run of the year.

Despite his high on-base percentage, Crawford has been batting in the nine-hole all year, limiting the team's ability to utilize his only strength at the plate. Even if he isn't able to make meaningful strides in his hitting, the Mariners could get some more run production out of him just by moving him up in the lineup. If not, more drastic adjustments will have to be made for him to be a meaningful contributor to the team.

Luis Castillo

After an offseason full of trade rumors, Castillo found himself on Seattle's roster for another year. Despite no longer leading the pitching staff as the ace of the rotation, he was still expected to put up strong numbers as the highest-paid player on the team. After a strong start to the season, his more recent outings have drawn more ire, and appropriately so.

In a start against the Cincinnati Reds, he conceded six earned runs in 4.1 innings with just three strikeouts. Against the Toronto Blue Jays, he held them to just three earned runs in five innings but gave up 10 hits, causing his pitch count to balloon to 102 by the time he was taken out of the game. These two games pushed his ERA from 2.12 to 4.44.

Diagnosing the reason behind his struggles would require an article of its own, but an initial glance tells a story of a more fastball-heavy arsenal that has decreased slider usage in favor of the sinker, a pitch that already had its fair share of issues last season. Paired with a slight decrease in velocity, Castillo is missing fewer and fewer bats while running into more barrels.

If the organization doesn't fix these problems sooner or later, they could be stuck with a pricey salary to pay for the remaining years of his contract without the numbers to warrant it. Still, he has shown flashes of vintage Castillo and it's clear that the ability to return to being an ace-level pitcher is still in there somewhere.

Julio Rodríguez

Even after having a disappointing year by his standards in 2024, Rodríguez was, by many accounts, still slated to be the best center fielder in baseball. As one of the few true five-tool players in the sport, his ceiling can only ever be so low.

However, even after proactive efforts to get more at-bats in spring training and get through his annual early-season slump quicker, the numbers haven't reflected the work put in. After his first 105 plate appearances, he's slashing .191/.314/.371 for an OPS+ of just 109. The main culprit is likely his 48.4 ground ball percentage, which is preventing him from making the most out of his top-tier exit velocity and natural power.

He has been walking significantly more and is still solid defensively, but it's clear that his offensive profile isn't where most were hoping it would be. His teammates have managed to pick up some of the slack to give the team a .715 OPS and the biggest contributors are unsuspecting names. If Rodríguez does manage to get back on track and returns to the dominance he exhibited in his first two years, it could be the difference that pushes the team over the top to the playoffs.