Pitching will be key storyline to eye at Mariners camp

This story was excerpted from Daniel Kramer’s Mariners Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

SEATTLE -- The equipment trucks left T-Mobile Park on Monday. The forecast in Arizona calls for mid-60s temperatures and sunshine. The echoes of baseballs smacking into gloves will reverberate on the back fields of the Peoria Sports Complex before this time next week.

Spring Training, at long last, is practically here.

Here are three storylines surrounding the Mariners entering camp:

1. How they manage young arms

Homegrown pitchers Logan Gilbert and George Kirby were huge catalysts in the Mariners' drought-ending postseason trip last year, each emptying the tank well into October. They also threw a career-high 185 2/3 and 156 2/3 innings (for Kirby, it includes the Minors), respectively, with workload management a well-chronicled topic throughout. Seattle’s front office is cognizant that both will be just as vital to the club getting back to the playoffs this year -- and of the possible reverberating effects from last year’s workloads.

“Last year on the first day of Spring Training, Logan Gilbert was throwing 98 mph in the first bullpen he threw,” manager Scott Servais said. “I really don't want to see that. We don't want to see it this year. We are going to have a little bit of a different ramp-up with him and George as well.”

The Mariners have already committed to using Matt Brash exclusively in relief for 2023 after toying with a transition back to the rotation, a decision both sides agreed upon based on Brash’s desire to pitch in the World Baseball Classic. Brash will have a quicker ramp-up for the WBC, but he also only threw 76 2/3 innings (including Triple-A Tacoma) last year, and he shouldn’t have workload issues as a reliever.

“I think the big thing with these guys is, we've seen it before, sometimes seasons can get away from you if you don't stay healthy,” Servais said. “Certainly on the mound and keeping those guys healthy -- all these guys -- starting pitching is so vital to having a chance to win every night.”

2. How the bullpen looks breaking camp

The relief corps has been the Mariners’ catalyst in each of their past two 90-win seasons. Now, basically everyone has returned, with a few new faces added to the fold, creating a logjam for just eight spots. Roster-dictating circumstances will favor Trevor Gott (signed to a big league deal), Chris Clarke (Rule 5 Draft pick) and Matthew Festa (out of Minor League options) beyond the locks (Paul Sewald, Diego Castillo, Andrés Muñoz).

But bullpens, even the good ones, can be fickle and cyclical.

“The next step in Spring Training is, I do think it is important to kind of start all over again,” Servais said. “You can't assume anything, and I talked to our coaches all the time about this. When you go into camp, we’ve got to start going over the same things on Day 1 that we've always done. Don't leave any boxes unchecked.”

The Mariners’ decision on the rotation will have an impact here, too, specifically on if they keep Marco Gonzales as the No. 5 starter -- as they did last year when there was a logjam -- or Chris Flexen, who moved to the 'pen after the Trade Deadline.

3. How the pitching prospects look

Also factoring into the bullpen mix is Bryce Miller, Seattle’s No. 5 prospect and MLB Pipeline’s No. 98 overall. No pitcher made as big of a jump in the organization last year as the 24-year-old flamethrower, who was reaching 100 mph while climbing three Minors affiliates.

Miller is among the Mariners' nine Top 30 Prospects who will be non-roster invitees in Spring Training, but he has a good chance of reaching the Majors sooner than the others. President of baseball operations Jerry Dipoto recently said that the club would break camp with its 13 best pitchers when responding to an inquiry on the hard-throwing prospect, yet that decision could hinge on Miller moving to relief, where his wipeout stuff could tick up even more.

If Miller remains a starter, a path to the Majors might be later in the season, given that, with Gonzales and Flexen, Seattle already has six capable starters.

Other pitching prospects on the cusp of the big leagues who will be in camp are righties Emerson Hancock (No. 2) and Taylor Dollard (No. 7), all of whom profile more as starters. It might not be by Opening Day, but they all have a realistic chance to impact the roster in 2023.