SAN DIEGO -- If things go to plan, the Mariners could be a very interesting team to watch at next year's Winter Meetings in Dallas. But for the time being, Seattle general manager Jerry Dipoto is staying true to his vow to keep relatively quiet this offseason and let his young roster begin to mature.

The normally hyperactive Dipoto left the Manchester Grand Hyatt on San Diego's waterfront after four days without having made any deals at this week's gathering. The Mariners did add hard-throwing right-handed reliever Yohan Ramirez from the Astros in the Major League phase of Thursday's Rule 5 Draft.

Seattle's plan is to let its most promising prospects begin showing what they can do in 2020, then have the financial flexibility to add free agents or make impact trades next year and beyond.

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Not that Dipoto ever sits completely still. The Mariners made a handful of moves in recent weeks -- signing free-agent pitchers Kendall Graveman and Carl Edwards Jr. and corner infielder Patrick Wisdom, while also acquiring lefty Nestor Cortes Jr. from the Yankees.

They'll make a few more similar acquisitions to improve roster depth before Spring Training begins in February, but none of those came in San Diego.

Biggest remaining needs

1) Bullpen: Dipoto has spent the past year churning through relievers in hopes of finding some gems, and he has uncovered some interesting candidates, but that spin cycle continues. Edwards, who pitched well for the Cubs from 2016-18 before struggling last year, is an interesting bounce-back candidate. Look for at least one more similar addition in the coming weeks.

2) Starter: Having let Félix Hernández, Wade LeBlanc and Tommy Milone depart in free agency, the Mariners could use rotation depth. Graveman, a former A's Opening Day starter, signed a free-agent deal as he returns from Tommy John surgery, and rookies Justin Dunn and Justus Sheffield -- Seattle's No. 5 and 9 prospects, per MLB Pipeline -- are the other top candidates to join Marco Gonzales and Yusei Kikuchi in the rotation. But Dipoto doesn't want to rush Dunn, who has pitched only a few innings above Double-A. He'd like to add a versatile veteran who could either initially take that spot if needed, or be a swing man in the bullpen or bulk-inning reliever behind an opener.

3) Catcher: The Mariners like the combo of Tom Murphy and Austin Nola to handle things at the big league level after trading Omar Narváez. But they could use a veteran with some MLB experience to provide depth at the Triple-A level or as injury insurance, an important factor at the position.

Rule 5 Draft

The Mariners like the upside potential of Ramirez, a 24-year-old who needs to command a fastball that has been clocked in the 95-98 mph range. The Dominican Republic native has never pitched above Double-A in the Astros' organization, but he'll get a chance to win a job in a bullpen that offers plenty of opportunity.

GM's bottom line

"For as long as we exist, we'll be open for business, not wanting to close the door to whatever opportunities may be out there. Teams check in. I can't say we have anything I would suspect is going to develop any traction just yet, but we'll see where it takes us and keep our ear to the street." -- Dipoto, on his unusually quiet Winter Meetings