The first round of MRIs were just to make sure there was nothing seriously "messed up," as Mattingly said, and they revealed just that. However, those MRIs did show a trip to the 15-day disabled list for the second time since July would be necessary, and Billingsley was put on it Saturday.
Mattingly said now it's just a matter of waiting as the first tests didn't show anything clear-cut, and he's not sure if the righty will be out for 15 days or more.
Before being taken out of his start on Friday in the fourth inning, Billingsley had gone 6-0 with a 1.30 ERA in his six starts since the All-Star break after coming off the DL.
He is being replaced by Josh Beckett in the rotation, and the newly acquired righty will pitch Monday in Colorado. As for when Billingsley comes off the DL, Mattingly wouldn't commit to what his rotation would look like with six starters on the roster.