He's hopeful that he won't need any more time than the allotted 15 days on the DL before he can start playing again.
"It feels much better," Grandal said on Tuesday. "They were expecting me to feel sore today and I don't feel sore at all."
Grandal suffered the injury in the second inning taking a swing in his second plate appearance of a five-run inning of what became an 11-5 victory over the Reds.
The Padres recalled catcher Eddy Rodriguez from Class A Lake Elsinore. With Grandal out, John Baker becomes San Diego's primary catcher.
"These things are tricky," Padres manager Bud Black said of oblique injuries. "A lot of times ... players might not feel discomfort, but the injury is still there. We wanted to nip this in the bud, give it rest and give it treatment."
Grandal is hitting .312 with five home runs and 15 RBIs in his first month in the big leagues. And while he understands the team wants to take it slow with his injury, he's already itching to return.
"We've got something going on here, our lineup seems like it's going real well," Grandal said. "But they are [the team] trying to take care of my career. They want me to get strong now."