The Pirates selected Griffin's contract from Triple-A Indianapolis on Friday.
Griffin is set to make his major-league debut Friday during the Pirates' home opener. The expectation is that he will also receive a nine-year, $140 million contract extension, per Buster Olney of ESPN, though that has not been finalized. Griffin will take over as the Pirates' everyday shortstop after collecting a .336/.420/.530 batting line with 21 home runs and 68 stolen bases in his first 127 minor-league games.