In 2010, right-hander Bartolo Colon traveled to his native Dominican Republic for an unusual procedure.
A doctor extracted fat and bone marrow, and reinjected the concentrated mix into Colon's injured shoulder. Suddenly, Colon's arm, and career, were rejuvenated.
The stem-cell therapy was controversial in 2010, but it has since gained increased acceptance among athletes, particularly pitchers.
"They all saw what happened to Colon," said Joseph Purita, the Florida-based doctor who performed Colon's procedure. "I mean, the guy's still pitching at [42] years old. Just hit a home run a couple weeks ago.