McKenna's journey began as a player, though his career was unfortunately cut short due to injury. This setback, however, proved to be a blessing in disguise. After retiring from playing, McKenna started his career in coaching whilst studying a Sports Science degree at Loughborough University. During his time studying, McKenna spent time as a youth coach at Tottenham Hotspur, Leicester City, Nottingham Forest, and Canadian side Vancouver Whitecaps.