The
Wacha, who missed a start last month with his shoulder injury, is 8-2 with a 2.84 ERA in 15 starts this season, his first in San Diego.
Left-hander Jose Castillo, right-hander Matt Waldron and infielder Matthew Batten were recalled from El Paso in corresponding moves.
Cruz, 43, signed a one-year contract with the Padres in the offseason.
He has 464 home runs in his career.
Reuters contributed to this report.