The Pirates completed a deal with the Mariners on Wednesday, sending Wilson and starting pitcher Ian Snell to Seattle in exchange for shortstop Ronny Cedeno, catcher/first baseman prospect Jeff Clement and three pitching prospects, MLB.com reports.
As recently as Wednesday morning, Wilson was rumored to be of interest to a number of teams, including the Red Sox and Giants.
"This was an opportunity for us to acquire a veteran shortstop, a former All-Star player, with leadership qualities and above-average defensive skills," Mariners general manager Jack Zduriencik said in a statement, as reported by the Seattle Times. "As we move forward over the next few years it is nice to know that we have solidified the shortstop position."
On July 19, Wilson, who had the longest tenure of anyone on the Priates, and Freddy Sanchez rejected extension offers from Pittsburgh. Wilson has a team option for $8.4 million next season, and ESPN reports that the Mariners could exercise it.
Snell had gone 2-8 with a 5.36 ERA in the majors this season, but has since recovered in Triple-A, going 2-2 with a 0.96 ERA in 37 1/3 innings.
Clement posted good power numbers this year, hitting 14 homers and 68 RBIs for Triple-A Tacoma.
Wilson becomes the sixth Pirates starter to be traded since last July, joining Adam LaRoche, Jason Bay, Nyjer Morgan, Nate McClouth and Xavier Nady.
Wilson, 31, is batting .267 with four home runs and 31 RBIs this season. Cedeno was batting just .167 with five homers and 17 RBIs in 59 games for Seattle this year.
The Mariners sit 7 1/2 games out of first place in the AL West and 6 1/2 games out of the lead for the wild card.
