"The elbow was great the whole time. That's a big relief to have that out of my mind, to know that's 100 percent," Kelly said Saturday.
Kelly returned to his throwing program Friday, throwing 30 pitches off a mound two weeks after his first bullpen, satisfied the groin strain that sidelined him last month is behind him.
"It's just something I have to keep in mind, [keep] getting treatment on it," Kelly said. "... I want to keep feeling good every day."
Kelly hopes to throw another bullpen session Monday, which again likely will entail all fastballs with a focus on mechanics as he continues to build up strength in his arm.
"It was definitely good to get back out there and throw off the mound," he said. "I feel good today. We'll take it day by day, but I felt good coming out of it."
It's too soon to know if Kelly, limited to 20 1/3 innings last season recovering from Tommy John surgery in 2013, will remain in extended spring training when camp breaks April 2 or head out to a Minor League affiliate where he could pitch every fifth day.
"Casey felt so great prior to Spring Training, so the groin injury was a little bit of a setback. But better now than later in spring," Padres manager Bud Black said. "Again, we're going to have to monitor his work, even when the season starts. He'll be fine."
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.