SEATTLE -- As the Mariners maneuver through what they say will be a quieter offseason than years past, general manager Jerry Dipoto on Wednesday acknowledged that the club will be active in the starting pitching market.

After the departures of Félix Hernández, Wade LeBlanc and Tommy Milone to free agency, Dipoto said at the General Managers Meetings in Scottsdale, Ariz., that only Marco Gonzales and Yusei Kikuchi are locks for Seattle’s Opening Day rotation.

“We will go outside and explore free agency to fill those holes,” Dipoto said. “But our goal is to fill those holes with what we think are potential candidates to be a part of what we're doing as we grow. We don't want to block anybody.”

Left-hander Justus Sheffield will also have a strong bid to break camp with the big league club after finishing 2019 with seven Major League starts, though his status will hinge on his Spring Training performance. Justin Dunn, who thrived at Double-A Arkansas with a 3.55 ERA then pitched exclusively in an opener role in four September outings with Seattle, will have a far shorter leash.

That means the Mariners need to fill at least two rotation spots, potentially more if their pitching prospects need more time to develop. Logan Gilbert (Seattle’s No. 3 prospect per MLB Pipeline), Dunn (No. 5) and George Kirby (No. 6), all righties, are expected to contribute by season’s end. But their opportunity might not come until the second half, when the Mariners will get progressively younger.

“Those are guys that we feel like could come in a rush,” Dipoto said. “We've built up a nice group of young pitchers. We'd like to start progressing some of the right-handers toward the big leagues because we're very left-handed in our rotation. But we don't want to block our young players, so that's going to make it challenging, and [it] makes our free-agent view a little bit different than most teams.”

The Mariners have also publicly said over the past year that they would like to reduce payroll while their younger players develop, so signing Gerrit Cole or Stephen Strasburg likely isn’t in the cards. But other free-agent options might be more financially palatable. And Dipoto didn’t rule out the trade market.

What about the outfield?
Dipoto said Kyle Lewis, Mallex Smith and Mitch Haniger, from left to right, should comprise Seattle's Opening Day outfield. But that could change.

Braden Bishop and Jake Fraley earned warranted callups in 2019 and will contend for playing time. And though they might be further off, Jarred Kelenic and Julio Rodriguez -- Seattle’s top two prospects -- are inching closer.

Haniger is expected to make a full recovery from the June 7 ruptured testicle injury that ended a disappointing season during which he slashed .220/.314/.463. The 2018 All-Star is arbitration-eligible for the first time this offseason and will net a pay raise from the $590,000 he earned in ’19, which MLB Trade Rumors projects at $3 million. He could be a movable piece with an early bounceback in ’20.

“Where the future takes us, especially with developing young outfielders, it just remains to be seen. But our young players will have to do a lot to put themselves on the tier that Mitch Haniger has already achieved. ... But we understand where we are in the cycle,” Dipoto said. “We understand the need to continue to get better; therefore, we have to stay open-minded with where our path may lead. But as we go into 2020, we believe Mitch is the stabilizing force.”

Domingo Santana might have the most uncertainty. He was among the Majors’ hottest hitters in April but posted a .740 OPS afterward and battled a right elbow injury over the final six weeks of the season. And his minus-13 Outs Above Average ranked second worst among 92 qualified outfielders.

Santana is arbitration-eligible also, as is Smith, who made defensive strides in the second half but projects better in a corner, scouts say. Smith’s OPS dropped 138 points from a strong 2018 to .635, which became a liability in the leadoff role.

Injuries and defensive struggles forced the Mariners to use primary infielders in the outfield in 2019 -- Dylan Moore, Tim Lopes and Shed Long -- so the club could seek more stability, though that will be fulfilled internally. Seattle’s minus-22 Defensive Runs Saved and minus-24.7 Ultimate Zone Rating were eighth and fourth worst in MLB, respectively.

“We're going to be open-minded about the possibilities, but ... like it was last year, our focus is very much what we're doing internally, about giving our young players the opportunity to play,” Dipoto said. “For us, we're going into 2020 with the expectation that we're going to almost be a first-half, second-half team. … So I'm not entirely sure yet what we make of filling our holes in the offseason, but we do have them to fill.”