40 in 40: Gregory Santos could be the key to the next great bullpen

There are three special sliders in there

The year is 2001.

The baseball men trudge on through the second-hottest summer on record (at the time). The world does not yet know the iPod, the first Harry Potter or Lord of the Rings movies, or Windows XP. The eyesore that is the Alaskan Way Viaduct still runs along the Seattle waterfront, not yet replaced by the eyesore that is... whatever they’ve replaced it with.

The world looks very different, and nowhere is it brighter than in Safeco Field. The Mariners are on a historic run that will ultimately culminate in 116 wins. Though they won’t end up winning the pennant, they’ll come to be known as one of the best teams in Major League Baseball history. And though the 2001 Mariners have virtually no weak points, their bullpen still manages to stand out as a strength.

Nelson. Rhodes. Sasaki.

No team was better at taking the lead than the 2001 Mariners, and no bullpen trio was better than protecting it than those three. The criminally underrated Arthur Rhodes led the way with an eye-popping 1.72 ERA. Jeff Nelson somehow pitched around what should have been a terrible 6.06 BB/9 to finish with an ERA of 2.76. Kazuhiro Sasaki anchored the pen with 45 saves, seemingly able to pitch out of any jam he found himself in.

After securing the best regular season in modern MLB history, the Mariners faced Cleveland in the ALDS. Game 1 ended in a lackluster loss. Rather than Nelson/Rhodes/Sasaki, the Safeco faithful were treated to Charlton/Paniagua/Halama in mop-up duty.

Game 2, however, saw the Mariners jump out to a 5-0 lead. Just like that, it was over. Once Jamie Moyer started to struggle, in came Rhodes. Then Nelson. Then Sasaki. Each pitched a scoreless inning.

Game 3 was eminently forgettable. Cleveland jumped all over Aaron Sele, and then obliterated Paul Abbott to go up 12-1. Then came more Halama. More Paniagua. A loss.

With the Mariners now in a must-win situation, Game 4 started poorly. Cleveland struck first against All-Star ace Freddy García. The score was 1-0 all the way until the 7th inning, when David Bell, Ichiro, and Mark McLemore finally each knocked in a run to give the Mariners a 3-1 lead. García gave up a leadoff double to start the bottom of the 7th. In came Nelson, who got an out. In came Rhodes, who got another. Rhodes went on to pitch a scoreless 8th, and Sasaki slammed the door in a perfect 9th.

Never were the stakes higher than in Game 5. A two-run single by McLemore put the Mariners ahead by two in the 2nd. After Moyer gave the team six scoreless innings, the Mariners just needed three more to punch a ticket to the ALCS.

Three innings was a convenient number of innings to need with Nelson, Rhodes, and Sasaki.

A perfect 7th from Nelson. Two more strikeouts from him to begin the 8th before Rhodes got the last out. Then, facing the heart of the Cleveland lineup in Omar Vizquel, Roberto Alomar, and Juan Gonzalez, Kaz didn’t flinch. He retired them in order, sending 47,867 Seattle fans into a frenzy.

That was October 15, 2001. It remains the Mariners’ most recent playoff win in Seattle.

The Mariners have had some pretty good relievers since then. JJ Putz. Edwin Díaz. Paul Sewald. They’ve shown a knack for developing relievers out of nothing, for finding diamonds in the rough. What they haven’t had, though, is another three-headed monster at the back of the bullpen. Until now.

You don’t need me to tell you about Matt Brash, whose slider might be the best pitch on the entire planet. His 34.7% K% speaks for itself, and he has a real chance to be the most valuable reliever in baseball this year.

You also don’t need an introduction to Andrés Muñoz, who the Mariners acquired along with Taylor Trammell and Ty France in one of the better trades in team history. Muñoz came slightly closer to Earth last season after posting a 38.7% K% in 2022, but his 100 MPH fastball and 88 MPH slider is among the best combinations in baseball.

Gregory Santos, who the Mariners acquired earlier this offseason from the Chicago White Sox, has a chance to the be third head of the Mariners’ Cerberus. Santos’ slider graded as the 4th best in all of baseball by Statcast. That, combined with a fastball that touches 100 MPH, makes him eerily similar to Brash and Muñoz, who each rely on a fastball/slider combination to keep hitters off-balance.

Santos, 24, has had an interesting path to success. After coming up through the Giants’ system, he made his debut in 2021 and was promptly suspended 80 games for testing positive for an anabolic steroid. After a ghastly 2022 (and I mean ghastly: he walked almost twice as many people as he struck out), the Giants DFA’d him and ultimately traded him to the White Sox.

Santos shined in 2023 Spring Training, made the team, and took the closer role after Liam Hendriks went down with an injury. The young righty dominated through the entire year before being shut down in September with elbow inflammation.

What changed? For one, Santos learned to control the ball a bit better, posting a walk rate better than he had ever previously accomplished at any level of professional baseball. For another, he revamped his slider — the 2023 version clocked a full 4 ticks faster than the 2022 version and spun a full 100 RPMs more. The end result of this revamp was a monster pitch that broke three full inches more horizontally and dropped four inches more vertically than it had a year prior.

The only mildly concerning thing about Santos’ profile is his health situation. The ominous “elbow inflammation” that ended his 2023 is gone, but he’s now experiencing latissimus dorsi and teres issues that have slowed his start to 2024. It sounds like he’s on the right track, but we won’t really know until he starts throwing off a mound.

The Mariners’ formula for October success isn’t hard to figure out. Get a lead behind one of Logan Gilbert, Luis Castillo, or George Kirby. Reach the seventh inning. And then?

Santos.

Brash.

Muñoz.

And with any luck? Winning their first playoff game in Seattle since Nelson, Rhodes, and Sasaki did it 23 years ago.