The Seattle Mariners' offseason rebuild is now in full swing after the club added a pair of Top 100 prospects in Jarred Kelenic and Justin Dunn, relievers Gerson Bautista and Anthony Swarzak and outfielder Jay Bruce from the Mets in exchange for Robinson Cano and closer Edwin Diaz.
The Mariners' impressive haul from the Mets comes a little more than a week after they acquired a new top prospect in left-hander Justus Sheffield (MLB Pipeline's No. 31 overall prospect), along with right-hander Erik Swanson and outfielder Dom Thompson-Williams, two players with realistic MLB value, from the Yankees in the deal for James Paxton.
• Breaking down the Mariners' return for Paxton
Whereas Seattle's trade with the Yankees marked a step in the right direction with its rebuild, Monday's blockbuster with the Mets moves the needle considerably for a Mariners organization in the midst of a 17-year playoff drought, with a farm system that was widely viewed as one of the worst among all 30 teams at the conclusion of the 2018 season.

Together, the two trades -- as well as some smaller moves already made by the M's this offseason -- have helped Seattle begin to restock its farm system with a much-needed mix of both high-probability and upside prospects. The Mariners have added seven players to their Top 30 Prospects list via trades in the past week and eight in the less than a month.
1. Justus Sheffield, LHP - Yankees
2. Jarred Kelenic, OF - Mets
3. Justin Dunn, RHP - Mets
11. Erik Swanson, RHP - Yankees
16. Dom Thompson-Williams, OF - Yankees
23. Ricardo Sanchez, LHP - Braves
27. Jake Fraley, OF - Rays
28. Gerson Bautista, RHP - Mets
Perhaps more important, the deals potentially set up the organization for what could be an accelerated rebuild should it continue to unload its more valuable assets.
In looking at the Mariners' return in this latest deal, Kelenic, MLB Pipeline's No. 62 overall prospect, is the obvious gem. And while he may not rank as the organization's top prospect, a strong case can be made that he has the highest ceiling of any player in the system.

As a Wisconsin prep, Kelenic was viewed by scouts as one of the better pure hitters available in the 2018 Draft before the Mets nabbed him with the No. 6 overall pick.
The new Mariners' No. 2 prospect lived up to that reputation during his pro debut, hitting .286/.371/.468 with 22 extra-base hits (6 HR) over 56 games between the Rookie-level Gulf Coast and Appalachian Leagues. In the process, the 19-year-old outfielder flashed the kind of five-tool potential that could one day make him an above-average big leaguer, if not more.

Dunn, now No. 3 on Seattle's Top 30, was the Mets' first-round pick in 2016, when they took him No. 19 overall out of Boston College. The 23-year-old right-hander struggled during his first full season but improved his lower-half and core strength and was a different pitcher during a breakout 2018 campaign in which he reached Double-A. Altogether, Dunn pitched to a 3.59 ERA with 156 strikeouts and 52 walks in 135 1/3 innings (24 starts).

Bautista obviously lacks the prospect allure of a Kelenic or Dunn, though he does come over with big league experience after logging 4 1/3 innings (12.46 ERA over five appearances) out of the Mets' bullpen last season. He otherwise spent much of 2018 between Double-A and Triple-A, posting a 5.14 ERA with 69 strikeouts over 49 frames (37 appearances). With a fastball that sits in the upper 90s and a track record of missing bats, Bautista has the raw ingredients needed to become a late-inning bullpen force if he can improve his fastball command and develop a more consistent breaking ball.
So just how much has the Mariners' farm system improved this offseason with their latest trade?
For starters, Seattle's crop of Top 30 prospects was the oldest among all 30 teams prior to the trade, with an average birthdate of 11/4/1995 -- or a little more than 23 years old. The Mariners also owned the third-lowest overall grade, checking in at 46.50.
In trading with the Mets, the Mariners were able to improve in both categories, growing younger while simultaneously adding to their core of top prospects.
More specifically, the additions of Sheffield and Dunn give the Mariners something they desperately needed in pitching prospects with at least mid-rotation upside who are also close to making an earnest impact at the highest level. They're the type of pitchers capable of accelerating a rebuild, and if it all plays out as hoped with their respective developments, could be worthy of building a rotation around in the years to come.
Meanwhile, it's important to keep in mind that Seattle's system, despite being regarded as one of the worst in baseball, already housed some interesting prospects before launching a rebuild.
Kyle Lewis, the club's injury-plagued first-round pick from the 2016 Draft, is a former Top 100 prospect with untapped potential, and 2017 first-rounder Evan White should at least be in the Top 100 conversation heading into next season. Right-hander Logan Gilbert, whom the Mariners selected with the No. 14 overall pick in June, didn't take the mound after signing but has the ceiling of a mid-rotation piece and could reach the Majors relatively fast.
The Mariners' recent international efforts could also pay dividends in the coming years. Julio Rodriguez, a toolsy, 17-year-old outfielder who raked this past season in the Dominican Summer League after signing the previous summer for $1.75 million, looks like a potential Top 100-caliber prospect. Shortstop Noelvi Marte, who ranked as MLB Pipeline's No. 8 international prospect before signing for $1.55 million this past July, is considered by scouts to have similar upside.

But perhaps the most promising aspect of the Mariners' rebuilding efforts thus far is that they still have remaining pieces that, if they can work out a trade for them, could net the club more Top 100-caliber prospects.
All-Star Mitch Haniger won't hit free agency until 2023 and therefore could net the Mariners a significant return, and the same could be said about shortstop Jean Segura, albeit to a somewhat lesser extent given his age and contract.
Veterans like Dee Gordon, Mike Leake and Kyle Seager are unlikely to fetch Seattle impact prospects in a trade, though it's at least fair to assume they could at least get some potential depth pieces while continuing to cut expenses.
When it's all over, the Mariners should have a vastly improved farm system -- one that possibly could set them up for contention, provided they also advantageously spend the money they'll save during the rebuilding process.
Sure, the on-field results in the interim probably won't be pretty and might test the fan base's patience, but, so far, the organization is taking the right steps toward achieving its long-term goal.