Liriano, 23, was hitting a combined .292 this season with 14 home runs and 66 RBIs between Double-A San Antonio and Triple-A El Paso. He also had a combined on-base percentage of .364 and slugging percentage of .476.
Liriano, who missed all of last season after recovering from reconstructive elbow surgery, was hitting .462 in 62 at-bats in 17 games with El Paso. He was pulled after two at-bats on Sunday.
Liriano is considered one of the most toolsy players in the Padres' Minor League system. He has a combined 31 doubles, three triples and 20 stolen bases this season.