In football brain and body always work together as one. Speed in a football action is therefore the ability in your brain to make a better decision before conduction the action; based on the best possible Position, Moment and Direction of your coming action. When you then execute the action, the abilities of your football physique (optimal movement in the optimal speed/power with a body that can handle the load), football mind (thoughts of determination and courage) and football technique (ball handling) co act in the optimal way of solving the situation. And that is also how you must construct exercises to stimulate and then coach, a player, if the objective is a more explosive football action. Remember: this football action is always situation based and unique. Brain and body works as one – always in football!
Ayanda Nikili in the video below displays exactly this at time 0.12 . A quite “slow” player if we test him on a linear sprint, but with the ability of a very high football speed.