SEATTLE -- As Jerry Dipoto likes to say, he got most of his "heavy lifting" done early in the offseason with a series of aggressive trades in a rapid-fire makeover of the Mariners' roster. But that doesn't mean Seattle's work is done this winter.
As the calendar flips to 2019, Dipoto still has some unfinished business even after making seven trades in the final seven weeks of '18. Here's a look at what's left on the to-do list before the Mariners report to camp in February.
1. Continue pursuing prospects via the trade market
Dipoto's primary goal this offseason has been to acquire younger talent -- quality prospects, as well as Major League-ready youngsters like center fielder Mallex Smith, catcher Omar Narvaez and shortstop J.P. Crawford -- in exchange for expensive veterans or players with limited time left before free agency.
Though most of the obvious trade pieces have already been moved, Dipoto surely would like to flip recently acquired designated hitter Edwin Encarnacion for future help. He could also still move starting pitcher Mike Leake, in the right scenario. Dee Gordon and Kyle Seager, two other returners with multi-year deals remaining, aren't likely to be dealt, as they're coming off down years and the Mariners don't want to sell low on them.

Felix Hernandez, Jay Bruce and Anthony Swarzak are other veterans whose contracts likely preclude them from being traded this offseason, though they could be candidates by midseason if they perform well.
2. Fill out the pitching staff
The biggest area of immediate need remains the relief core, given the departure of Edwin Diaz, Alex Colome, James Pazos and Juan Nicasio via trades and Nick Vincent, Adam Warren, Zach Duke and David Phelps in free agency.
The Mariners have brought back Swarzak and Gerson Bautista in trades, but Dipoto will continue to flesh out that group in the coming weeks. Relievers tend to fluctuate more than any other players and Dipoto will undoubtedly look for some buy-low candidates willing to sign one-year deals while looking to re-establish their careers, who can then help in the short term and potentially be flipped by the July 31 non-waiver Trade Deadline if they perform well.
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The same holds true with starters, though to a lesser extent, as Seattle can already trot out a five-man rotation of returners with Marco Gonzales, Wade LeBlanc, Roenis Elias, Leake and Hernandez. Dipoto has signed 30-year-old southpaw starter Tommy Milone as a non-roster invitee, but very well could add another similar veteran or two for further organizational depth and injury protection so that highly regarded prospects Justus Sheffield, Justin Dunn and Erik Swanson don't need to be rushed.
3. Balance the outfield
The Mariners are extremely left-handed heavy throughout their projected lineup at this point, with the only right-handed-hitting starters being right fielder Mitch Haniger, first baseman Ryon Healy and designated hitter Encarnacion, if he sticks with the club.
Dipoto would like to add another outfielder, somebody who could split time with Bruce and Ben Gamel in left or Smith in center, and his preference would be a right-handed hitter to help balance that issue.
As with the bullpen and other positions, Dipoto will look for a veteran who needs an opportunity and is willing to sign a one-year deal, which could mean waiting to see how things play out and who remains available as January progresses.
4. A short-term shortstop
Crawford figures as the shortstop of the future after the 24-year-old was acquired from the Phillies in the Jean Segura deal. But Dipoto doesn't want to hurry the talented youngster, who missed much of last season with a strained forearm and broken left hand, so he's talked of adding a veteran infielder who could bridge the gap if Crawford doesn't command the job in Spring Training.
The Mariners do have a couple utility infielders who potentially could fill that role with Kaleb Cowart, Kristopher Negron and Dylan Moore all on the 40-man roster. But if the right deal pops up, Dipoto will look to bring on more of a pure shortstop to help mentor and provide a buffer -- if needed -- for Crawford.
5. Beef up the backstops
Narvaez figures as the full-time starting candidate after being acquired from the White Sox for Colome, and David Freitas returns as the backup, but catching remains a fairly thin area and Dipoto will likely bring on another veteran to provide some depth.
The club did already sign 33-year-old veteran Jose Lobaton and Minor League free agent Austin Nola as non-roster invitees, but another experienced catcher never hurts, as top prospects Cal Raleigh and Joe DeCarlo aren't close to being ready.