Joe Kelly has been diagnosed with a left hamstring strain and is headed back to St. Louis for further tests. Kelly suffered the injury Wednesday while trying to beat out a groundball to first base. He is likely to be placed on the 15-day disabled list, and the Cardinals will now have to dip into some of their starting pitching depth. Carlos Martinez could be an option, but Tyler Lyons started for Triple-A Memphis on Wednesday and is probably the more logical short-term fill-in candidate because Martinez has been making appearances in a major league setup role.