San Diego opened a roster spot by optioning outfielder Oscar Gonzalez to Triple-A El Paso on Thursday.
Cronenworth, 31, batted .257 with a .409 on-base percentage in nine games this season before going on the IL. He has two homers and five RBIs.
The two-time All-Star is in his sixth season with the Padres. He is batting .247 with 71 homers and 315 RBIs in 658 career games.
Despite lengthy absences of Cronenworth and All-Star center fielder Jackson Merrill, the Padres possess a 23-13 record that rates fourth in the majors. Merrill returned to the lineup Tuesday after missing 24 games with a right hamstring injury.