## 1 Introduction  
The main function of the soccer coach during a match is to manage the various changing situations that occur in order to win, maintain an advantage or recover from a disadvantage [1]. The analysis of player substitutions made by coaches is an emerging research topic in high-performance soccer [2; 3; 4].  
In a substitution, one player who is on the bench replaces a player who started the match. The substituted player may not re-enter the field of play [5]. Soccer player substitutions can be made for different reasons, such as a player being injured, being fatigued or having a yellow card or to modify tactical systems [6]. In soccer, there is limited number of player substitutions. In this regard, until the advent of the COVID-19 pandemic, the regulations allowed a maximum of three player substitutions during an official match and one additional player substitution in the event of extra time, in accordance with rule 3 of the 2014 International Football Association Board (IFAB) regulations. However, at the beginning of this pandemic, the IFAB established a temporary rule (extended until December 2022) allowing soccer teams to make up to five player substitutions [7]. Despitethis, [PERSON] et al. [8], in relation to the COVID-19 pandemic, have reflected on the importance of further increasing the number of player substitutions to reduce the likelihood of injury.  
Elite soccer is a team sport where positive results are paramount and the competition demands that players play at the highest level [9]. It is also an intermittent sport that requires the capacity of players to repeatedly perform high-intensity actions [10]. Therefore, most of the research conducted on player substitutions has focused on external [11] and internal [12] intensities, especially in the distances covered at different speed ranges [2; 3; 13]. During soccer matches, the physical and technical performance of players decreases, and the current evidence [2] suggests that substitute players report a greater percentage of time spent in distances covered at higher intensity compared to players playing the entire match. Thus, player substitutions are justified as an effective strategy to reduce the effects of team fatigue [14]. However, the main reason for making player substitutions during soccer matches is not to mitigate the fatigue of the players on the field, but to change the tactical behavior of the teams [4]. Along this line, [PERSON] et al. [15] suggest that the tactical behavior and playing style of teams during soccer matches change after the player substitutions. Thus, variability of tactical systems leads to high performance and competitive advantage [16]. Match congestion, including during national league and major cup competitions, is another factor affecting player substitutions in modern soccer [17]. It is impossible to have an accurate record of the teams' national competition calendar in its different competitions (regular league; cup format, knockout competitions), time of the season and/or players' participation in international competitions with their countries. Therefore, in this study, only the calendar of the competition analyzed was taken into account, although it is clear that the aforementioned factors influence the use of substitutions.  
The analysis of different situational variables has expanded the scientific knowledge on this research topic. The variables selected for analysis in this study are those most commonly used in this type of research and describe the phase of the competition (competition stage), the place where the match is played (match location), partial result of the match (match status) and the result of the match (final result).