The Mariners Begin Building Their Bullpen of Tomorrow

Addressing a historically bad bullpen was the primary goal of the Mariners this offseason. Going back to 1969 — the year MLB lowered the mound — the 2020 Mariners bullpen posted the second worst league-adjusted FIP and the fourth worst league-adjusted ERA in a single season. They’ve already made a number of moves to strengthen their relief corps, including trading for Rafael Montero and bringing in a ton of relievers on minor-league deals. Yesterday, they capped off their offseason plan by signing a big-name closer to a multi-year deal. They locked up Ken Giles to a two-year deal, though the specific financials have yet to be reported at time of publication. The only problem is that Giles recently underwent Tommy John surgery and likely won’t pitch until 2022. Elbow troubles have plagued Giles over the last two years. He pitched through inflammation in 2019 but all that wear and tear on his arm caught up to him a season later. He threw just 3.2 innings in 2020 and went under the knife on October 1.

He’s the latest player to sign a deal like this. Garrett Richards and Michael Pineda are the two biggest names who have signed multi-year deals soon after undergoing major arm surgery. It’s an interesting move for the Mariners who have had a rather quiet offseason. They’re not quite ready to break out of their rebuild and have avoided opening the purse strings to make a splash this year. By locking up Giles now, they have him committed to their 2022 roster when they’re hoping to be more ready to compete.

It’s become apparent that general manager Jerry Dipoto’s ability to spend this winter has been seriously hamstrung by the Mariners ownership group. With a number of quality free agents still available just a week before spring training begins, that the biggest signing the Mariners have made won’t even help them in the upcoming season is a huge blow to a fan base that’s exhausted from watching non-competitive teams for nearly two decades. With those payroll limitations in mind, getting Giles now is probably the only way Dipoto could work out this deal. They’ll likely get the benefit of a lower salary commitment in 2021 to account for Giles’s rehab time with most of the salary backloaded into next year’s budget.

Giles has been one of the best relievers in baseball since his debut in 2014. He’s posted the fifth lowest league-adjusted FIP among all qualified relievers in that time, and when you adjust for historical context, his K%+ is the 10th best mark among those same peers. Despite dealing with the early onset of his elbow issues, 2019 was one of his better seasons. After a rough 2018 that included falling out of favor in Houston and getting traded to Toronto, he bounced back with a fantastic season as the Blue Jays’ closer, posting the highest strikeout rate of his career.

Giles has spoken at length about how he gradually felt out of place in Houston and how getting traded to Toronto allowed him to fix some of the issues that had led to his rough 2018 season. Here’s how he explained it to Rosie DiManno of the Toronto Star back in September 2018:

“I knew the things I had to work on. I know myself. I’m a really good pitcher, good profile pitcher. If something’s wrong, I know how to fix it. It’s my body. When I came [to Toronto], they stayed patient with me. I said, hey, I want to work on this thing till I’m comfortable. All right. OK, I’m comfortable, let’s move on to this next thing. Pitching, you can’t just try to fix everything at once. For me, I had to take baby steps to get my groove back. The Jays allowed me to do that. Yeah, the team was out of contention, but it doesn’t matter. It’s still my career. I still have to prove myself. Them being so patient with me, understanding what I want to do, was very, very big.”

Regaining a feel for his slider was one of the big adjustments he worked on in Toronto. In 2018, his slider usage dipped to 40.9% and opposing batters posted a .252 xwOBA against the pitch, the highest he had allowed in his career. After getting his body and throwing motion right again, he increased his usage of the pitch to 49.4% the next year, throwing it more often than his four-seam fastball for the first time in his career. The revamped slider allowed just a .130 xwOBA. In his limited time on the mound in 2020, he continued to lean on his breaking ball, further increasing its usage to 58%.

A full recovery from Tommy John surgery is never guaranteed, but the Mariners are hopeful they’ll see a revitalized Giles in 2022. As Corey Brock of The Athletic wrote earlier this month, Seattle has recently targeted a number of pitchers who have come off of Tommy John surgery. Kendall Graveman, Keynan Middleton, and the aforementioned Montero each had T.J. surgery in 2018 and Andres Muñoz, acquired at the 2020 trade deadline, is recovering from his own surgery in 2019. Here’s how Dipoto explained it to Brock:

“It’s changed, in my view, and also the view of the industry in recent years. Part of it is the advances in medical care and the process itself — nine of 10 guys will have a full recovery. In most cases, the pitcher comes back similar, if not better, than he was before. I think in the second year, you start to see a return of command. That first year back, you get a lot of stuff and location. By year two, the pitcher is back.”

Brock also interviewed the four pitchers named above, and they all described having a greater awareness of their bodies post-surgery. The rehab process helped them focus on how their throwing actions strain their bodies and how to hopefully prevent re-injury in the future. The Mariners confidence in their medical staff to help these pitchers regain their effectiveness allowed them to take some risks in the hopes of them paying off in the near future.

With Giles waiting in the wings, the Mariners 2022 bullpen looks like it could be a fantastic unit. Giles and Montero both have experience as effective closers and Muñoz has the repertoire to be a force in high-leverage situations. Seattle also has a number of relief prospects who could take a step forward this year. Led by Sam Delaplane and Wyatt Mills, ranked ninth and 13th, respectively, on our updated 2020 prospect lists, the Mariners could have a handful of high-quality options to fill out their relief corps. Adding Giles to that group gives it an elite, proven relief arm with a high ceiling, provided that his rehab process goes according to plan. And investing in him now gives the Mariners some cost certainty for 2022, when they’ll hopefully be looking to open up their payroll to supplement their young core.