Mariners at Memorial Day: Bullpen
Mariners at Memorial Day: Bullpen
Seattle’s lineup has been under tremendous scrutiny. But the bullpen has recently experienced its own set of issues, which could be more devastating to the team's postseason aspirations.
We’ve recently discussed the Mariners’ run production effort and the starting rotation. The third and final segment of the “Mariners at Memorial Day” series addresses Seattle’s bullpen.
Note: Statistics include all action through Saturday, May 25.
A solid group
The Mariners began the season with Matt Brash and offseason addition Gregory Santos on the IL. The team also dealt with the short-term loss of Tayler Saucedo to an injury. Despite these setbacks, the remaining relievers have done a nice job of complementing an outstanding starting rotation.
As you can see, the Mariners are top-10 in multiple areas. Thanks to the rotation delivering a high number of quality starts, the bullpen ranks at the bottom of the league in batters faced (BF) and innings pitched. As usual, I gravitated to the bullpen’s .296 xwOBA, which is one of the best in baseball.
Expected Weighted On-Base Average (xwOBA) uses quality of contact (exit velocity and launch angle) to determine what should’ve happened to batted balls. A key advantage to xwOBA is defense (good or bad) doesn’t influence it. This gives us a truer sense of how a hitter or pitcher is performing. The MLB average xwOBA this season = .318
The Mariners have eight relievers with an xwOBA better than the MLB average. Please note several players listed below are currently assigned to Class-AAA Tacoma.
xwOBA of M’s Relievers
Tayler Saucedo - .232
Andrés Muñoz - .261
Trent Thornton - .277
Gabe Speier - .288
Eduard Bazardo* - .303
Ryne Stanek - .306
Kirby Snead - .306
Cody Bolton* - .317
Austin Voth - .320
Brett de Geus*- .346
Collin Snider* - .387
* Tacoma
MLB average = .318
It’s no surprise to see Andrés Muñoz near the top of the leaderboard. Since suffering a four-walk meltdown during his third appearance of the season on April 6, Muñoz has been Seattle’s most valuable reliever. So much so, the right-hander has an MLB-leading four multi-inning saves.
Under pressure
With the loss of Brash to Tommy John surgery and Santos being expected to be out until July, manager Scott Servais has needed to be creative in order to navigate his club through late-inning, high-leverage situations. Hence, using Muñoz for more than one inning.
Late in Spring Training, the Mariners attempted to mitigate the loss of Brash by signing former Astro Ryne Stanek. The hard-throwing Stanek has been a helpful addition, although the former Arkansas Razorback’s four-seam fastball hasn’t been as effective as seasons past.
Stanek still brings the heat with an average fastball velocity of 98.6 mph. But opponents are having much more success against the four-seamer (.317 AVG) than last year (.216). His whiff rate has also taken a sharp dip.
Despite his velocity being unchanged, Stanek is inducing far fewer swings and misses with the four-seam fastball in 2024 than in recent years. Eleven Mariners have thrown at least 50 four-seamers this season - all have a higher whiff rate than the Missouri-born right-hander (17.1-percent). Among MLB relievers, Stanek ranks 114 of 199.
This seems suboptimal considering the four-seamer is Stanek’s primary weapon (about 60-percent utilization). Hopefully for the 29th overall pick of the 2013 draft and the Mariners, he can regain his fastball mojo. Considering his velo is stable, it appears to this unqualified nerd that arm health isn’t an issue.
Several holdovers from last season have also played key late-inning roles: Tayler Saucedo, Gabe Speier and Trent Thornton. Perhaps just in time, the left-handed throwing Saucedo returned to the Mariners this weekend.
Saucedo’s .232 xwOBA is tenth-best among 433 pitchers facing 50-plus hitters. Not only that, the Tahoma High School alum has been extremely effective against right-handed hitters. Only 13 of 114 southpaws facing 30-plus righty bats have a better SLG than Saucedo (.276).
Naturally, right after I asked whether Speier might be the best left-handed reliever in Mariners franchise history, he began to stumble. Most noteworthy to me, his effectiveness against right-handed hitters cratered in May.
It’s important to recognize the preceding table is a relatively small sample divided into two months. Therefore, a few good consecutive outings by Speier would quickly reverse his numbers. Then again, if the Californian continues to struggle against right-handed hitters, his value to Servais in high-leverage situations will diminish.
Thornton, another reliever we recently featured, has scuffled a little bit lately compared to April. But he hasn’t slipped to the degree Speier has this month. The North Carolina native did give up a three-run home run to Gleyber Torres during the recent Yankees series. But the Mariners won the game and it’s the only homer allowed by Thornton this year.
Furthermore, Thornton has been exceptional at limiting loud, quality contact. His 31.1-percent hard-hit rate is 24th-best among 164 relievers facing 75-plus hitters. Similarly, his 4.9-percent barrel rate ranks 50th.
The other guys
The rest of the bullpen is comprised of mostly interchangeable arms who’ve been helpful. But lately, the ship has been taking on water.
The relievers I’m referring to are those tasked with getting the ball to the high-leverage guys or helping keep the Mariners competitive in close games. Specifically: Kirby Snead, Austin Voth, Cody Bolton, Eduard Bazardo, Brett de Geus, and Collin Snider. It turns out that the “other guys” were a far more effective group in April.
Late last week, the Mariners did acquire right-hander Mike Baumann, who had been designated for assignment by the Orioles. The team also claimed Eduardo Salazar off waivers from the Dodgers. Perhaps these moves are a response to the supporting cast faltering recently. Or maybe, these pickups were simply opportunities to add more layers of depth.
Baumann, who has no MiLB options remaining, is with the big-league club. Salazar has yet to appear with Class-AAA Tacoma. A look at Baumann’s 2024 season with Baltimore reveals his conventional numbers were average-ish. He’s also issued a lot of free passes (11-percent walk rate).
Still, Baumann’s expected stats were significantly better than their league averages. Same with his barrel rate. Perhaps these advanced metrics point to a potential breakout by the 28-year-old. That said, reducing walks will be crucial to any good news story involving Baumann.
Didn’t see that one coming
All things considered; I do wonder why the Mariners designated right-hander Tyson Miller for assignment earlier this month. Miller, who was out of MiLB options and acquired by the Cubs, had performed relatively well with Seattle.
To be clear, I’m not suggesting Miller was the second coming of Paul Sewald or anything like that. But in his limited time with the Mariners, the California Baptist University product had a very respectable .285 xwOBA and held opposing hitters to a .186 AVG. Granted, opponents did SLG .395 against him and produced a 9.7-percent barrel rate. But keeping Miller around a little longer seemed to make sense.
Having said all that, I’m not criticizing the Mariners for moving on from Miller. There are probably factors the public isn’t privy to that influenced this decision.
Walking a fine line?
While the lineup continues to search for its identity, the bullpen and rotation have propelled the Mariners to first place in the AL West. But it’s reasonable to question how much longer the current stable of relievers can consistently get the ball from the starter to Muñoz in close games. Especially with cracks beginning to emerge in its foundation this month.
So much seems to hinge on Santos returning from the IL in July. But I suggest not banking on the 24-year-old pitching for Seattle until he does.
If Santos does become a crucial second-half contributor, great. But if he’s ineffective or suffers another setback, the front office will have to decide whether to commit more resources to augment the bullpen or stand pat with the current group.
Based on what we’ve seen in May, remaining idle could lead to another late-season letdown similar to the one we witnessed last September and October.
My Oh My…