PEORIA, Ariz. — Should the goal be returning to the postseason, or winning the division? In seasons past, those two achievements were the delineation between failure and success.

When the Mariners were mired in the longest postseason drought in professional sports, playing in the postseason was a simple, but largely unattainable accomplishment.

After the team ended a 21-year absence by returning to the playoffs in 2022, the definition of a successful season increased to winning the American League West.

The snarkiest of Mariners fans would probably say the goal for 2024 is to win 54% of their games, making sure the tired joke — that lost its humor about 24 hours after it was regrettably said by Jerry Dipoto — continues to live on.

The disappointment of being eliminated from the postseason following the penultimate regular season game is not something they want to feel again. Making the postseason is a requirement for any semblance of success. But winning the division, well, that’s another goal that is still mentioned, though not quite as frequently or as publicly.

“This group is just hungry,” Mitch Haniger said. “The guys in here want to win. Ultimately, being a loser is not fun. It’s really motivating just to try to get back into the playoffs and win a World Series — the No. 1 goal. It’s win the division first and get in the playoffs and then make a run and win that last game of the season.”

The Mariners’ season starts Thursday night against the Boston Red Sox in Seattle.

Three reasons why the Mariners will win the AL West:

The best rotation in the AL?

The Mariners’ starting rotation of Luis Castillo, George Kirby, Logan Gilbert, Bryce Miller and Bryan Woo are a formidable quintet of power arms that can shut down an opposing lineup for six-plus innings.

Is it the best? Given that the No. 1 starters for the Astros and Yankees are out with arm injuries, the Guardians could have a formidable rotation by the end of the season if Shane Bieber can bounce back. But it’s difficult to find a better rotation in the AL.

A productive offense

Yes, the Mariners, at least on paper and recently in spring training, have looked like they will have an offense that is something more than competent. There have been times over the past few seasons when competent would have been a welcomed improvement.

With the return of Mitch Haniger, the additions of Mitch Garver and Jorge Polanco, the offseason changes made by Dominic Canzone and Ty France, the continued improvement of J.P. Crawford and Cal Raleigh and the intense desire from Julio Rodriguez for a more consistent season has manager Scott Servais confidently optimistic about the team’s ability to score runs.

“It’s the deepest lineup we’ve had since I’ve been here,” he said.

While Rodriguez’s production can be the determining factor for Seattle’s success, the offense won’t be so reliant on him to deliver in every situation.

Opponent regression

The Astros and Rangers will still be good. They return largely the same rosters that carried them into the American League Championship Series last season.

But Houston will enter the season with two members of its rotation — Justin Verlander and Jose Urquidy — on the injured list. They’ll be inexperienced at catcher, finally moving on from Martin Maldonado. While they added Josh Hader to the bullpen, they also lost key setup relievers Hector Neris and Ryne Stanek.

The Rangers will be without Corey Seager (sports hernia surgery Jan. 30) and Nathaniel Lowe (oblique strain) when the season starts. Their timetable to return is uncertain. Starting pitchers Jacob deGrom (Tommy John surgery) and Max Scherzer (back surgery) are still recovering from their respective surgeries and won’t be ready until midseason.

Three reasons why the Mariners won’t win the AL West:

Injury issues

The Mariners are already dealing with injuries to key relievers Matt Brash (elbow inflammation) and Gregory Santos (lat strain), neither will be ready when the season starts. Seattle won’t have both back in the bullpen until mid-May. The obvious injury concerns surround the three big offseason additions — Haniger, Polanco and Garver.

None of those three has played more than 110 games in the past two seasons. Polanco was limited by a hamstring issue last season. Haniger played in only 57 games in 2022 with the Mariners and 61 in 2023 with the Giants. His bad luck with fluke injuries has been well documented.

Garver has played in 100 games or more only once in his career. His injuries are position specific, or as he said plainly, “When I catch, I get hurt.”

Bullpen regression

In 2021, it was Paul Sewald and Drew Steckenrider. In 2022, it was Matt Brash, Erik Swanson and Andres Munoz. In 2023, it was Justin Topa, Gabe Speier and Tayler Saucedo. Each of the past three seasons, the Mariners have had pitchers of varying levels of talent and pedigree emerge as valuable relievers to their bullpen.

Their “pitching lab” has been outstanding in finding pitchers hovering around the edges of MLB rosters and helping them find consistent success.

Who will it be this year?

Is it Cody Bolton or Collin Snider? Will nonroster invitee Tyson Miller, who pitches strikingly similar to Sewald, be added to the 40-man roster? Perhaps Ty Buttrey or Joey Krehbiel will emerge from Tacoma’s bullpen to help.

None of those pitchers can replicate the overpowering stuff of Brash and Santos. They might not be able to be the next Topa. The magic doesn’t always work on everyone. Early in the season, the Mariners will need to rely on unproven relievers to pitch important innings.

The wild, wild West

It took 90 victories and a tiebreaker to win the division last season with the Astros, Rangers and Mariners cannibalizing each other, while the Angels were moderately competitive for three months. Could you imagine any of those top three teams playing in the lackluster AL Central?

Even with all their injury and roster issues heading into the season, would you bet your paycheck against the Astros or the Rangers vying for a division title?

Though an eventual decline has been predicted seemingly for the past five years, Houston keeps finding ways to win. The Astros have won six of the last seven division titles, played in the last seven ALCS series, made the World Series four times and won it twice.

The Rangers’ offense is good enough — even without Seager and Lowe initially — to offset their pitching woes. Evan Carter, the hard-hitting prospect darling from the 2023 postseason, has now been replaced in popularity by Wyatt Langford, who looks as physically imposing as teammate Adolis Garcia, and might be a better hitter. When they get Seager and Lowe back to full strength, it’s the best offense in baseball.