Re-teaching a Student

I've had one particular student who has been learning very quickly and seems to be inclined to music perhaps above many of my other students.  While he used to go off and learn his assigned piece by the following week, he is now struggling with even simple pieces.  He is spending more of his time playing his own improvisations rather than practicing his lesson plan.  He is also losing learned technique, including hand position and timing.  I can see now where letting some of the "little" things go has compiled into a "big" thing now.  We have a big recital in less than two weeks, followed by syllabus exams 6 weeks after that.  Those 6 weeks will be spent redirecting, rehoning, and reiterating, to the parents as well, the need for practicing what's been given, and playing it how it's been taught.  The next couple of weeks for me will be spent researching refreshing ways to (re)teach and (re)motivate him!