Harrison has been sidelined since April 15 because of a broken hand, missing 30 games over that stretch. He will bat leadoff and start at second base Sunday in the Pirates' series finale against the Padres.
Harrison, 30, is batting .263 with one home run in 14 games this season. The two-time All-Star had a career-high 16 homers last season with Pittsburgh.
The Pirates optioned right-hander Nick Kingham to Triple-A Indianapolis to create a spot on their 25-man roster for Harrison.
Kingham, 26, is 2-1 with a 3.44 ERA in three starts for Pittsburgh this season. He allowed three runs in six innings in Pittsburgh's 6-2 loss to San Diego on Saturday.