Police say Alexis Urbina was found unconscious and covered in blood in his family's south Phoenix home in September. He died of his injures two days later at a hospital.
There was no obvious sign of forced entry into the house, but Urbina's family told police some of his boxing memorabilia was missing.
Police spokesman Sgt. Trent Crump has confirmed the two arrests were made Friday night. He says the investigation is ongoing.
Urbina won the 141-pound Youth Men's Division at the USA Boxing National Championships in April at Spokane, Wash. His family says he had Olympic aspirations.