Our Team

PlaySafe Athletic Trainers

Derek Hirai, MS, ATC


PlaySafe Schools

  • Burton
  • SFI
  • June Jordan
  • Wallenberg


Derek started in the summer of 2008 at the UCSF Sports Medicine clinic. Prior to arriving at UCSF, Hirai worked as the athletic trainer for Indiana University's Baseball team. Hirai completed his Masters of Science degree in Kinesiology from Indiana University and his Bachelors of Science degree in Exercise Science with an option in athletic training from Oregon State University. His interests include sports medicine research as it pertains to ankle instability and rehabilitation of the throwing athlete. 

Gina Biviano, MA, ATC


PlaySafe Schools

  • Lowell
  • Academy

Gina joined the UCSF PlaySafe athletic training staff in the summer of 2010 after completing her graduate studies at San Jose State University.  While pursuing her Master’s in Kinesiology, Gina worked as a graduate assistant athletic trainer from 2008-2010 at Santa Clara University.  During her time at SCU, she worked and traveled with the women’s varsity basketball and cross country teams.  Gina is also a graduate of Chapman University with a Bachelor of Science in Athletic Training.  In January of 2007, she traveled with a group of Chapman athletic training students to Australia and spent a month studying sport, the work of physiotherapists, and recovery techniques with professional and Olympic athletes. Currently Gina is active in the California Athletic Trainers’ Association as a member of the Governmental Affairs Committee.  Her goal is to gain governmental recognition of the athletic training profession and licensure of athletic trainers in the state of California. 

Elise Hammond, ATC


PlaySafe Schools

  • Lincoln
  • O’Connell

Elise joined the UCSF PlaySafe athletic training staff in the fall of 2008.  Prior to her arrival at UCSF, Elise served as a graduate assistant athletic trainer at the University of California, Berkeley from 2005-2008, where she worked with football, women’s gymnastics, and track & field/cross country. In December of 2004, Elise received her Bachelor's degree from Oregon State University in Exercise and Sport Science, with an emphasis in Athletic Training; she also completed minors in Psychology and Music.  

Erin Stoval, MS, ATC


PlaySafe School

  • Archbishop Riordan

Erin joined the UCSF PlaySafe athletic training staff in fall of 2015. Before joining the PlaySafe team, Erin worked as a fellow at Saint Mary's College in Berkeley, California. During this time she was also the head athletic trainer at Branham High School in San Jose, California.  While completing her Master of Science in Athletic Training at Stephen F. Austin University in Texas, she worked in a multitude of medical settings, as well as traveled with SFA football, Women's soccer, and Women's basketball. In May of 2011 Erin received her bachelor of science degree in Kinesiology from Sonoma State University. Erin was the 2015 recipient of the California Athletic Trainer's Association lifesaver award, given to an athletic trainer with an outstanding lifesaving achievement.

Michael Mayes, MS, ATC


PlaySafe School

  • Stuart Hall

Michael joined the UCSF PlaySafe athletic training staff in the spring of 2015. Prior to his arrival at UCSF, Michael worked as the athletic trainer for Valley Christian High School-Dublin from 2014-2015. Michael received his Masters of Science degree in Exercise Science from the University of Toledo, Ohio. While at Toledo, Michael worked as the graduate assistant athletic trainer from 2012-2014 with the women’s volleyball team and men’s tennis team. In 2012 Michael received his Bachelors of Science degree from San Jose State University in Kinesiology with an emphasis in Athletic Training.  In his spare time he enjoys reading, weight lifting, and spending time with family and his cat & dog.

Hally Tappan, MA, ATC


PlaySafe Schools

  • Mission
  • Marshall

Hally Tappan joined UCSF PlaySafe in August 2016.  She was born and raised in Reno, Nevada.  In spring 2014, she received her Bachelors of Science in Athletic Training from the University of Nevada, Las Vegas.  During her undergraduate internship, she worked with UNLV football, baseball, and softball, as well as local high schools.  In 2016, Hally was awarded a Masters of Arts in Athletic Training from San Jose State University.  Between fall 2014 and spring 2016 worked with San Francisco State University’s Women’s soccer and softball teams as a graduate assistant athletic trainer.  

Kathryn Anne Elston, MA, ATC


PlaySafe Schools

  • Galileo

Katie joined UCSF in 2017 after receiving her bachelors and master degrees from San Jose State University.   Prior to her work at UCSF, Katie was a graduate assistant athletic trainer at San Francisco State University for two years working with women's volleyball, men's and women's cross country, men's wrestling, and women's track and field. 



Kayla Gradillas, MA, ATC


PlaySafe School

  • Balboa

Kayla is a California native from Southern California.  She graduated from Sultana High School where she played softball until injury ended her playing career and introduced her to athletic training.  Kayla received her B.S. in Kinesiology with a focus in Athletic Training from California State University, Fullerton in 2009.  She also completed the Athletic Training Program at CSUF.  In 2013, Kayla received her M.A. in Coaching and Athletic Administration from Concordia University, Irvine.  Kayla joined UCSF in 2018 after nearly 10 years of athletic training experience in the high school setting.  Most recently, Kayla was the Director of Athletic Training, Athletic Administrator and Science Teacher at JSerra Catholic High School in San Juan Capistrano, CA.  Kayla is a member of the National Athletic Trainers' Association, Far West Athletic Trainers' Association and California Athletic Trainers' Association.


Dominique Farris, ATC


PlaySafe School

  • Washington


Trevor Hooker, ATC


PlaySafe School

  • Urban


Justine Li, ATC


PlaySafe School

  • Convent



Yair Lazar, ATC


PlaySafe School

  • Drew
  • International