sentence1: On September 17 , Arreola will perform at the Staples Center in Los Angeles , California , against Alfonso Gomez at the undercard of Juan Sandoval vs. Saul Alvarez .
sentence2: On September 17 , Arreola will face Juan Sandoval on the undercard of Saul Alvarez vs. Alfonso Gomez at the Staples Center in Los Angeles , California .