Gary trained at Guy’s Hospital School of Physiotherapy in July, 1986 and became a member of the Chartered Society of Physiotherapy. He joined Arsenal Football Club as the First Team Physiotherapist in September 1986. He remained at Arsenal Football Club for 22 years before he left for a full-time role at the Football Association in August 2008. In August 1996, Gary was named as the Lead Physiotherapist to the England Senior Men’s Team, a role he filled alongside his work at Arsenal. In August 2008 Gary accepted the appointment as the full time Head of Physiotherapy Services to the Football Association. From 1996 through the 2016 European Championships, he headed up the medical team at five FIFA World Cups, four UEFA European Championships and two FIFA Under 20 World Cups. Gary was also the Lead Physiotherapist to the Team GB Football Team at 2012 London Olympic Games. After leaving the FA, Gary was appointed Head of Medical Services at West Ham United where he served until the June 2018. The football drug pulled him back in in September 2021, when he became Head of Medicine & Sports Science at Arsenal Women.