## 1 Introduction  
Long-term athlete development (LTAD) stands for models that aim to establish the best concepts for coaches, PE teachers and parents [1, 2]. During LTAD phases, the accurate identification of talents is a crucial tool for sports clubs to assess the potential of young athletes [3]. One of the fundamental general issues in talent identification is the problem of comparing current performance to potential. The main reason is that maturity status has been confirmed as a significant contributor to performance in most physical fitness components [4]. Therefore, current LTAD models primarily concentrate on determining maturation changes and incorporating them into the interpretation of current physical performance, thereby estimating the potential of a young athlete [5, 6]. The consideration of biological maturation is crucial in adolescence, given the highly individual timing and duration of maturation changes [7]. This applies especially around the period of peak height velocity (PHV), which occurs between 11 and 16 years for boys [4]. The process of talent identification is, to some extent, sport-specific [5]. In football, talent identification is primarily focused on the physiological, psychological, technical and tactical skills of a player [8]. The strongest fitness predictors of elite performance in football appear to be linear speed, agility, change of direction speed (COD), maximal power and the high rate of power development considering the short period spent on the ground to produce power [8; 9; 10]. In the case of speed, acceleration speed is crucial as it reflects the specific demands of movement on the field [11]. However, during talent identification, speed over distances longer than 20 m proves to be more important because the advantage of faster players becomes more apparent in longer distances, and therefore, speed tests in football include both distances up to 20 m and distances over 20 m [10; 12; 13]. Regarding COD, assessment is based on different variations of shuttle runs or the \(T\)-test [14; 15]. In the case of explosive power, the measurements focus primarily on the maximal explosive power of the lower limbs during various forms of vertical and horizontal jumps [16]. Moreover, multiple jumps and/or drop jump exercise are used to measure reactive strength [17]. Recent literature on testing in youth soccer is increasingly focusing on the maximum sprint speed in adolescents [18; 19]. Current findings indicate that during the PHV period, there is a significant increase in maximal speed, highlighting the considerable impact of maturation on speed assessment [19; 20]. The influence of biological maturation on acceleration speed remains unclear. A recent study by [PERSON] and [PERSON] [21], which directly examined the influence of biological age on acceleration speed in U13 football players, did not find significant differences between players of different maturation statuses. On the other hand, [PERSON] et al. [22] found that maturation significantly affects football players' maximal speed development during PHV, while explosive power tends to develop most after PHV. Another study [23] reported a performance spurt in explosive power starting around 1.5 years before PHV and peaking during and up to 1 year after PHV. These findings suggest uneven physical fitness development during PHV, highlighting the importance of considering growth in testing. Current data regarding the influence of maturation on agility in football are inconclusive. A recent study by [PERSON] and [PERSON] [21] with young football players did not find any significant differences in COD across different groups divided by maturation. Similarly, [PERSON] and [PERSON] [18] did not observe any differences in COD between groups before and after PHV. In contrast, a recent study by [PERSON] and [PERSON] [24] on 13-15-year-old football players found significantly better performance in COD in early matured players compared to late matured players.