It could be a million things, it might even just be 'ghost pain'... the body often gives us pain signals from the site of a recent injury even though it might be healed.
However, without looking at you and talking face to face the only definite thing I can say is that in the body has systems to heal it's self... if the problem is not going away then these systems are obviously failing. If it is compromising your ability to perform, then it is time to get a professional opinion....
(As a rule of thumb if a niggle hasn't gone away after 2 weeks relative rest then I would get advice)
ps Ghost pain as I describe it is not something I've ever read about in a text book or been taught about. It is just something I have observed in my practice. Therfore you might or might not be able to find more information about this anywhere... in fact if any body does know more about this phenomen please let me know.
