Richard Callahan was born in Phoenix, Arizona, the second of three children to Gerald Callahan, a high school physical education teacher, and Patricia Callahan, a registered nurse. Growing up in the Ahwatukee Foothills neighborhood of Phoenix, he was immersed in athletics from an early age, participating in tennis, basketball, and swimming throughout his childhood. His father introduced him to racket sports at age six, and by age twelve he had become a regionally ranked junior tennis player in Arizona [2].
Callahan attended Desert Vista High School, where he was a four-year member of the varsity tennis team and twice named Arizona Division I Tennis Player of the Year. He earned an athletic scholarship to Arizona State University, where he played collegiate tennis from 2005 to 2009, achieving an All-Pac-10 selection in his junior year. He graduated with a Bachelor of Science in Kinesiology in 2009. Though he briefly pursued a professional tennis career from 2009 to 2012, injuries to his right shoulder led him to explore alternative racket sports [3].