The process in which a relatively unspecialized satellite cell acquires specialized features of a myoblast. This occurs as part of skeletal muscle regeneration. A myoblast is a mononucleate cell type that, by fusion with other myoblasts, gives rise to the myotubes that eventually develop into skeletal muscle fibers. [ GOC:ef GOC:mtg_muscle http://purl.obolibrary.org/obo/CL_0000056 http://www.ncbi.nlm.nih.gov/pubmed/16607119 ]