Background. The anatomy and mechanical properties of the Crural Fascia (CF), the ubiquitous connective tissue of the posterior region of the leg, have recently been investigated. The most important findings are that (i) the CF may suffer structural damage from indirect trauma, (ii) structural changes of the CF may affect the biomechanics of tissues connected to it, causing myofascial pain syndromes, and (iii) the CF is in anatomical continuity with the Achilles paratenon. Consistent with these points, the authors hypothesize that the onset of acute Achilles paratendinopathy may be related to histological and biomechanical changes of the CF. Case Presentation. A professional male football player suffered an isolated injury of the CF, interposed between the soleus and medial gastrocnemius (an atypical site of injury) with structural connective integrity of the muscles. After participating in the first official match, two and a half months after the trauma, he has unexpectedly demonstrated the clinical picture of acute Achilles paratendinopathy in the previously injured limb. Conclusions. Analysis of this case suggests that the acute Achilles paratendinopathy may be a muscle injury complication from indirect trauma of the calf muscle, if a frank and extensive involvement of the CF were to be ascertained.