Kelly is a dealing with a lower-body issue that will limit his usage until the postseason, Ken Gurnick of MLB.com reports.
Kelly had been dealing with a leg injury earlier in September, but it's unclear if his new issue is related, though he's appeared in only one contest since Sept. 15 and pitched one-third of an inning. However, it doesn't sound as if Kelly is entirely unavailable, so he should take the mound on at least a couple occasions prior to the close of the regular season.