Padres prospect Kelly slowed by strained groin

PEORIA, Ariz. -- Pitcher Casey Kelly remained sidelined Monday with a strained groin, though he felt a bit encouraged that the injury won't keep him away from the mound for long.

"It feels a little better today than it did yesterday," Kelly said Monday morning.

Kelly was held out of workouts on Sunday after he reported the strain. It wasn't one specific incident that led to it, he said.

"It was kind of a gradual thing," Kelly said. "It just got tighter and tighter. Right now, we're just getting treatment on it."

There's no timetable to when Kelly will be able to resume workouts, including throwing off the mound.

Kelly, who had Tommy John surgery in 2013 and was limited to 20 1/3 innings last season in the Minor Leagues when his rehabilitation hit a snag, threw a bullpen session on Friday and came out of that fine, he said on Saturday.

Kelly is expected to get stretched out as a starting pitcher in camp and then begin the season with one of the team's Minor League affiliates, starting every fifth day.

"This is going to be a slow process with Casey, but the key thing with him is that when he did throw his side [Friday], he felt great," said Padres manager Bud Black.