The main aim of this study was to find out the increase level of the differentiated special physical training for different age categories of footballers depending on their positions on the field, especially defenders. A complex test of special physical features has been performed in order to achieve this objective. Revaluation of the training process of children and juniors practicing football is a complex phenomenon that requires training solutions based on multiple information, experiments, research and studies. It has a number of features, mainly due to the peculiarities that are shown by different periods of their development. That’s why the problem of differentiated physical training for 13-14 year-old footballers has been approached. The settled current major scientific issue in this area covers a differentiated approach to the development of the young footballers’ specific physical qualities which will further optimize the educational process and enhance its effectiveness. Following the review of literature in the field, teachers’ observations during the experiment, and relying on survey data, there have been prioritized the development of physical qualities specific to young players depending on their game positions, the ways of their manifestations, determining the specific differentiated physical training level in the course of one-year training cycle, which, in their turn, extend and complement the existing layout in the theory and methodology of sports training in football. Methodology and research organization. The purpose of research is to optimize the structure and the content of the physical training for the 13-14 year-old junior football players, based on differentiated exercise training of defenders in a yearly training cycle. The research results. Analyzing the data and the opinions of experts in the field, it was found that one of the main objectives of the research was to outline the level of the development and differentiated special physical training of footballers of different age groups and specialized as defenders in a yearly training cycle. To achieve this objective we have carried out a complex testing of motor skills specific to the position of defender in number of 16, divided into the experimental group (n = 8) and the control group (n = 8). In the ascertaining experiment, complied with the requirements of CTYF “Zimbru”, it was determined the physical growth (height and weight) and there were applied five motor tests. Conclusion. Differentiated physical training according to the player’s field position in the game had a positive impact on the technical training department of juniors, who at the end of the experiment improved significantly their play quality indices, that is technical parameters related to the basic technical elements and methods of a football game.