Sendejo is a 2006 graduate of Smithson Valley High School in Spring Branch, northeast of San Antonio, Texas. He was a two-time All-San Antonio area selection for coach Larry Hill. Also a two-time honorable mention All-State pick, and a two-time All-District 26-5A honoree. As a senior, he had 75 tackles (3 for loss), four interceptions, eight pass deflections, one forced and one fumble recovery, helping lead the Rangers to a 13-2 record and the Class 5A semifinals. He was named Comal County defensive player of the year for his senior season efforts. He was also a regional finalist and academic All-district. Sendejo selected Rice over Tulane, Army, North Texas, Northwestern and New Mexico.
