The Seattle Mariners agreed to trade starting pitcher Taijuan Walker to the Arizona Diamondbacks on Wednesday as part of a five-player trade.
The Diamondbacks announced they acquired Walker and infielder Ketel Marte from Seattle in exchange for shortstop Jean Segura, outfielder Mitch Haniger and left-handed pitcher Zac Curtis.
Walker has showcased a lot of promise across parts of four seasons in the big leagues. The 24-year-old right-hander possesses a mid-90s fastball and a wipeout curveball, giving him a lot of untapped potential as he continues to learn how to attack the strike zone.
MLB.com ranked him as the fourth-best prospect in all of baseball in 2013, but Bill Shaikin of the Los Angeles Times cautioned: "Reminder about prospects: Three years ago, Mariners wouldn't trade Taijuan Walker to get David Price. Today, Walker gets Jean Segura."
A foot injury slowed Walker's development some during the 2016 season. Ryan Divish of the Seattle Times previously reported the starter made a Triple-A rehab appearance during the campaign. The good news was he got in some on-field work without feeling any pain, which likely played a role in his becoming a hot trade target.
His results before the injury were encouraging. He posted a 3.66 ERA, which is nearly one full run better than a year ago, and 1.14 WHIP while striking out 80 batters in 86 innings. His walk rate (1.88 per nine innings) was also on track to become a career low, according to FanGraphs.
He ultimately made 25 starts in 2016 and posted a 4.22 ERA and 1.24 WHIP.
Mariners general manager Jerry Dipoto commented on the trade, per Tim Booth of the Associated Press: "It's always hard. It's hard anytime you give up talent like Taijuan. Frankly you have to give to get."
Receiving a talent like Segura in return makes things easier.
The 26-year-old slashed .319/.368/.499 in 153 games in 2016, drilling 20 home runs and stealing 33 bases. He stole as many as 44 bases in 2013, and ESPN Stats & Info noted he led the National League with 203 hits in 2016. He also finished with career highs in WAR (5.7) and OPS (.867).
Jeff Passan of Yahoo Sports reflected on the swap: "Arizona sold high on Jean Segura and bought low on Taijuan Walker and Ketel Marte. Marte a legit SS, four years younger than Segura to boot."
In terms of Walker, some may wonder why the Mariners traded a pitcher with so much upside who's under team control through 2020, per Spotrac. The most likely explanation would be the front office's uncertainty about whether he can truly become an ace, so Seattle capitalized on his value while he's still a prized young arm.
All told, moving a pitcher with Walker's potential is a risk, even when considering the package the Mariners got in return. But it's one Seattle decided to take after getting a close look at the starter since drafting him in the first round in 2010.