Sanchez, infielder Josh Harrison, infielder Jordy Mercer and outfielder Andrew Lambo have all been named to the Mesa Solar Sox roster. The Pirates will also send three pitchers, though those pitching spots have not yet been finalized.
Sidelined since late June with a jaw injury, Sanchez will use the AFL as a way to make up for missed at-bats. Sanchez is almost fully recovered from jaw surgery, though director of player development Kyle Stark said on Tuesday that it is "doubtful" Sanchez will play again with Class A Bradenton this season.
"It's going to be another wonderful opportunity," Sanchez said. "I try to compare it to the Cape [Cod League]. It's more competitive out there now, but I'm feeling the same way as when I found out I was going to play in the Cape. You're looking forward to playing against the best guys in the country."
Sanchez will participate in the organization's instructional league before joining the Solar Sox.
Mercer, a third-round Draft pick in 2008, is finishing his first full season at Double-A Altoona, where he has hit .275 with 34 extra-base hits and 62 RBIs in 120 games.
Harrison ranks third on Altoona's roster with a .302 season average. Acquired from the Cubs as part of the John Grabow/Tom Gorzelanny trade last July, Harrison has driven in 73 runs and connected for 39 extra-base knocks.
Lambo is new to the organization, having been obtained just a month ago from the Dodgers in exchange for closer Octavio Dotel. The 22-year-old outfielder has hit .310 since joining Altoona and is now batting .282 overall this season.