I doubt there is anything physically wrong with Luke. However im concerned the issues are mental as in his ability to remember the play or reading the offense or making a call. if he's stumbling over the play call or forgetting assignments he has to be sidelined.
(100% speculation. Uninformed and pure day dream-ery on my part)
Close your eyes and imagine watching (i know i know) Sportscenter. The Panthers are fresh off a victory in which Cam Newton throws for 350 yards 3 TDs 0Ints rushes for another 58 yards and a score. Now here is the tricky part. Julio Jones is a Panther. Jones catches 225 yards 2 TDs.