There are currently various forms of football. Notable examples include outdoor football (soccer), futsal, futebol society (small-sided turf football), and beach soccer. Although similar, each variation requires specific movements from the athlete, given the differences in playing surfaces and the dimensions of the court or field. Athletes are known to suffer muscle injuries during both training sessions and actual competitions. The primary objective of this study is to highlight the main types of muscle injuries—specifically first-, second-, and third-degree strains—and the muscle fiber types affected in outdoor football and futsal, while also comparing injury patterns across different player positions and identifying the most frequently injured muscles. The analysis revealed that contusions and muscle strains are the most common injuries and that the lower limbs are more affected than the upper limbs. Comparisons showed that, in outdoor football, midfielders and forwards suffer the most injuries, whereas in futsal, wingers record some of the highest injury rates. This study is justified by the need to determine how and where to implement preventive measures during the physical conditioning of football players—whether in the outdoor or indoor (futsal) game—to minimize the occurrence and consequences of sports injuries, given that such injuries are highly debilitating and impair athletic performance.