In the deal, the Diamondbacks acquired starting pitcher Taijuan Walker and young shortstop Ketel Marte from Seattle.
The Mariners, on the other side, acquired shortstop Jean Segura, outfield prospect Mitch Haniger and left-handed reliever Zac Curtis from Arizona.
There's obviously a lot to unpack in this blockbuster, which was the first of Mike Hazen's career as Diamondbacks general manager.
Regardless, Hazen is still showing his willingness to contend in 2017 and beyond by acquiring two Major League pieces in Walker and Marte.
Walker, 24, is an exceptional talent who was a first round draft pick back in 2010. He can dial his fastball up into the mid- to high-90s, but the results have never seemed to follow.
In 2016, Walker made 25 starts for Seattle, going 8-11 with a 4.22 ERA in 134.1 innings pitched. According to FanGraphs, he was worth 0.6 Wins Above Replacement. Perhaps more alarming was his K/BB ratio of 119-37. This was something that was noticeably better the year before.
It is definitely possible that a change of scenery is all Walker needs to succeed going forward, and pitching for Arizona certainly represents a change. Now, it's on the Diamondbacks to tinker with Walker and make him the pitcher he can be.
The second piece in this deal for Arizona is Marte, who was signed as a free agent out of the Dominican Republic by Seattle in 2010. He was one of Seattle's better prospects heading into the 2015 season (when he lost his rookie status).
Last year, Marte seemed to struggle against the big league pitching, slashing just .259/.287/.323 (66 wRC+) with one home run and 33 RBI over 466 plate appearances. Marte definitely has good speed (he stole 29 bases in the minors in 2014), but if he cannot get on base at the clip he needs to, a lot of it could go to waste. Per FanGraphs, he was worth -0.7 Wins Above Replacement.
On the Seattle side of the deal, GM Jerry Dipoto and company also received a couple Major League pieces to, in their eyes, better their team.
The 26-year-old Segura is the obvious upgrade in the trade from the Mariners' perspective. He had a career year in 2016, slashing .319/.368/.499 with 20 home runs and 64 RBI over 694 plate appearances, providing a bright spot in a relatively grim season for the Diamondbacks. Segura led the NL in hits and was worth 5.0 WAR, according to FanGraphs.
Like Walker, Haniger, 25, is a former 1st round pick that is still trying to get his feet wet in the Major Leagues. Unlike Walker, Haniger made his MLB debut just last season and hit .229/.309/.404 with five homers and 17 RBI over 123 plate appearances. He has good pop; Haniger homered a combined 30 times across three D-Backs levels in 2016, but it is hard to know how much of an immediate impact he will make with Seattle.
As for the final piece in the trade, Curtis, 24, is also just breaking on to the Major League scene. He pitched in 21 games for Arizona last season (13.1 IP) and allowed 10 earned runs for a 6.75 ERA. He walked more batters (13) than he struck out (10) in his brief MLB stint. Despite this, Curtis could find himself in a left-handed one out guy role (LOOGY), as he has shown good splits against lefties in the minors throughout his career.
This is a fascinating trade because no player traded is over the age of 26 and all come with lots of team control. (Of the group, Segura hits free agency first . . . at the end of the 2018 season.) Breaking this down, it is a trade of teams who are willing to take a risk on young players to try and make their team better now.