Shaw was named a team captain on Saturday and later that night was attending a family function at a cousin's apartment in his hometown of Palmdale when he saw his nephew, who can't swim, struggling in the pool.
With no one around, Shaw told USC's website that he instinctively jumped from the balcony onto the concrete below and crawled to the pool, where he pulled Carter to safety. Unable to step out of the pool because of the pain in his ankles, Shaw lifted himself up the ladder with his upper body.
"I would do it again for whatever kid it was, it did not have to be my nephew," Shaw told the team website. "My ankles really hurt, but I am lucky to be surrounded by the best trainers and doctors in the world. I am taking my rehab one day at a time, and I hope to be back on the field as soon as possible."
Shaw was taken to the hospital where he was diagnosed with two high ankle sprains and will be out indefinitely. He said Carter was traumatized, but physically in good shape.
"That was a heroic act by Josh, putting his personal safety aside," Trojans coach Steve Sarkisian said. "But that's the kind of person he is. It is unfortunate that he'll be sidelined for a while and we will miss his leadership and play, but I know he'll be working hard to get back on the field as soon as possible."