PEORIA, Ariz. -- Losing Casey Sadler for the entire season due to upcoming shoulder surgery is hardly what the Mariners needed when concluding their first week of Spring Training, especially given that the right-hander was among the most consistent fixtures to a bullpen that was, in large part, why Seattle stayed in contention late last season.

Sadler, who will undergo the season-ending procedure in the coming days, is riding a franchise-record 29 straight scoreless appearances, which led to a 0.67 ERA and an opposing slash line of .143/.207/.196 in 2021. It’s not just the production that they’ll need to replace, but his critical function as the bridge from a game’s starter to the rest of the bullpen -- the “pivot” role.

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“I've often said, you lose probably more games in the fifth and sixth inning in our league than you lose in the eighth or ninth inning,” Mariners manager Scott Servais said. “It's just a critical spot and oftentimes a high-leverage spot. You're coming in with runners on and whatnot, so it's a big role.”

The Mariners have in-house options to fill the role, and they’re banking on one of those candidates -- or an under-the-radar arm -- to step up, much like Sadler did last year. In an ideal world, Servais would like two such arms for the pivot role.

Here’s an early breakdown of how they might handle that spot:

The favorites: Matthew Festa, Erik Swanson, Yohan Ramirez
Festa has the qualities Servais is seeking: high-90s velocity, a new-look slider that the Mariners say is more conducive to swing and miss, and perhaps above all, experience. The 29-year-old has also been in camp longer than most, having arrived well before the lockout ended because he’s not on the 40-man roster. One drawback might be that Festa is more of a fly-ball pitcher.

“I want [the pivot guy] to get it on the ground, but it doesn't always work out that way,” Servais said. “The biggest thing is you’ve got to have somebody come in to throw strikes and have a secondary pitch that they're very comfortable with throwing for a strike. You can't just have one guy come in there leaning on the fastball all the time in those spots. That's been my experience -- somebody that could spin it or or mix it up a little bit is super valuable.”

Swanson had some huge moments last year, brings multi-inning ability and developed an impressive fastball-changeup-slider mix last year that kept hitters honest. His quality of contact numbers were also among the best on the team. Ramirez, who had a few notable escape moments after entering with runners on, is also “in that bucket,” per Servais.

The other possibilities: Wyatt Mills, Joey Gerber
Despite hiccups in their first taste of the Majors, the Mariners are still bullish on the makeup of Mills and Gerber. Mills’ funky delivery and fastball-slider combination led to a 44.4% ground-ball rate at Triple-A Tacoma last year. Gerber, like Mills, also has a unique delivery and repertoire that lends itself to ground balls, and he was scoreless in 11 of his final 13 outings in ‘21. Both Mills and Gerber are on the 40-man, so the Mariners wouldn’t have to sacrifice a spot to add them.

“You’re not going to say, 'OK, give me the guy's got the best inherited runners that don't score [rate],’” Servais said. “But somebody that can hold runners and do all the game awareness stuff certainly helps.”

The later-on option: Roenis Elías
It sure seems like it’s not a matter of if Elías contributes, but when. The veteran lefty and clubhouse favorite has recovered from Tommy John surgery that he underwent last spring but is being brought along slowly, so he likely won’t be ready by Opening Day. In his last full season, in 2019, Elías had a 3.96 ERA and 111 ERA+ in 50 outings, including 44 with the Mariners. He could be a strong second lefty candidate down the road to pair with Anthony Misiewicz, too.

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Much of the pivot role will hinge on how the Mariners manage their late innings, too, and the club does not plan to deploy a traditional closer. Instead, some combination of Paul Sewald, Drew Steckenrider, Andrés Muñoz and Ken Giles will be inserted in matchup-dictated pockets.

“Every year is so new and bullpens are so volatile,” Servais said. “You just never know. Somebody gets on a run. We saw Casey Sadler go 29 straight [scoreless] appearances. Who could ever predict that? Nobody. So you just don't know. You have to have some feel. ... The manager typically rides the hot hand. It's the guy that's finding a way to get them out and that handles the stress of the moment.”