Using an average reference for internship applications

If I'm pretty confident my clinical instructor wrote me an average reference for an internship I'm applying to (read: something along the lines of "**** is an adequate but not outstanding student nurse") should I even bother applying to this internship? Is there any way to compensate for a not-amazing review from a clinical instructor when applying to internships? I really don't know what he wrote - maybe it's more positive than I'm assuming, but I get a vibe from him that he wasn't super thrilled to write it for me.

This particular internship requires a reference from a clinical instructor, and he is the only one I've ever had. There are other internships that don't require a clinical instructor reference and I could focus my energy on those instead.

Thoughts?? I'm really in a pickle here as to where to put my time and essay-writing energy!