PMH: Asthma, clavicle fracture 2 years ago.

Patient presents to the office with the chief complaint of right sided leg pain with significant bruising and swelling, which started three days ago. He collided shins with another player during a soccer game over the weekend which resulted in some mild bruising. He states that the next afternoon he bumped the same shin into an examination table while working at the veterinarian office where he is employed. That evening he developed  significant swelling and pain towards the bottom of his shin above his ankle. He indicated that the swelling is the size of 'a softball' and that there is significant bruising and pain around the area. He states that walking on and movement of the leg is provocative for pain. Ice and NSAIDs have been mildly palliative. He rates the pain as a 7 out of 10 most of the time but can reach 10 out of 10 while standing or walking. He describes the pain as deep and throbbing in nature. He states that he was wearing shin guards while playing soccer and did not think he hit his shin hard enough to cause a fracture.  

Question: What might your differential diagnosis include at this point?