SEATTLE -- The Seattle Mariners finally landed the established shortstop they've long been trying to find.
To do it, they had to part with a talented young pitcher who still has the potential to blossom.
Seattle and Arizona pulled off a five-player trade Wednesday night, with the Mariners acquiring speedy infielder Jean Segura and the Diamondbacks getting right-hander Taijuan Walker as the centerpieces of the deal.
Segura immediately projects as Seattle's leadoff hitter and starting shortstop, solidifying an infield that already includes All-Star sluggers Kyle Seager at third base and Robinson Cano at second. But getting Segura meant the Mariners had to give up on the inconsistent Walker, a power arm who has showed occasional flashes of brilliance.
"It's hard anytime you give up talent like Taijuan," Seattle general manager Jerry Dipoto said. "Frankly, you have to give to get ... and Segura fit this club."
The addition of Walker could help a dreadful Arizona pitching staff that posted a 5.09 ERA last season, tied with Minnesota for worst in the majors. He joins a rotation that includes ace Zack Greinke, Shelby Miller, Patrick Corbin and Archie Bradley.
The Diamondbacks finished 69-93 last season, fourth in the NL West.
A touted prospect, the 24-year-old Walker went 8-11 with a 4.22 ERA and 119 strikeouts in 25 starts for Seattle last season. He would be outstanding one game and then struggle the next.
"Young, controllable pitching is hard to find, and adding Taijuan to the rotation gives us significant depth in that area," new Arizona general manager Mike Hazen said.
Segura, an All-Star in 2013 with Milwaukee, is an immediate upgrade at shortstop for Seattle, which went 86-76 last season and finished three games out of a playoff spot. He hit .319 with 20 home runs, 33 stolen bases and 63 RBIs for the Diamondbacks, who acquired him from the Brewers in a January trade.
Segura spent most of last season at second base for the Diamondbacks, but will move back to shortstop with the Mariners.
"This trade made more sense for where our roster is, and Jean Segura fit this club about as well as any player we were looking at," Dipoto said.
Going into the offseason, Seattle thought its starting pitching depth was enviable. Now the Mariners will need to find supplemental arms after dealing Walker.
"Most of our focus, if not our primary focus, from now until opening day is going to be left toward the pitching staff," Dipoto said.
That might not be so easy for Seattle. Hazen said the thin market for pitchers was one of the reasons the Diamondbacks made the trade for Walker.
"We felt this was the opportunity we were going to have to take due to the market," Hazen explained.
Whether it turns out to be a successful trade could ultimately depend on how Marte and Haniger develop.
Marte had many of the same problems with inconsistency as Walker, but also became a liability in the field. Marte hit .259 in 119 games last season, but hitting was secondary to being solid in the field. At times Marte was excellent, but too many routine plays were not made. He finished with 21 errors.
Still, the Diamondbacks were struck by his athleticism and the fact that 2016 was his first full season in the majors at one position.
"Our scouts loved his ability and athleticism in the middle of the field," Hazen said. "We think he adds a lot to the middle of our infield."
Haniger, who turns 26 next month, hasn't gotten much of a chance to prove himself at the major league level, but Dipoto believes he can play all three outfield positions. Haniger was the Diamondbacks' minor league player of the year after hitting .321 with 25 homers and 94 RBIs between Double-A Mobile and Triple-A Reno. He made his major league debut on Aug. 16 against the New York Mets and appeared in 34 games, hitting .229 with five homes and 17 RBIs.
"We feel like Mitch, like so many of the guys we have acquired dating back to last year, there is not much left for him to do in the minor leagues," Dipoto said. "We really like our depth and potential for impact and feel good with where we are with our outfield."