Better still, Kelly's right elbow -- he's working his way back from April 2012 Tommy John surgery -- felt fine afterwards and again on Friday.
"The elbow feels great," Kelly said. "I think the big thing for me is just getting used to being in a game situation again."
Kelly, the Padres' No. 4 prospect according to MLB.com, threw 72 pitches (47 strikes).
"Casey threw the ball well, he's building his pitch count and now he'll add to that," Padres manager Bud Black said Friday. "He felt fine physically. He's getting closer to being on a true active roster ... and not a rehab player."
Black said there's a good chance that Kelly's next outing could come next week for the team's Double-A affiliate in San Antonio.
Kelly threw 58 pitches in his first rehab outing for Lake Elsinore last Saturday. After throwing 72 pitches on Thursday, he could be cleared to throw in upwards of 85 pitches the next time out, possibly next Tuesday.