Alex Ruiz was the quarterback at Linfield Christian School when he dislocated his knee on a tackle last October, according ABC7 KABC's Curt Sandoval.
The injury severed an artery and cut off blood flow to Ruiz's leg for 11 hours, according to ABC7 KABC. Ruiz, 17, decided to have the leg amputated below the knee in February, according to ABC7 KABC.
Fast forward to last Friday when Ruiz and his family attended a flag football tournament in San Diego. He was introduced to the crowd at the game by the Challenged Athletes Foundation, a non-profit that raises money to help athletes get sports prostethics, according to ABC7 KABC.