Context:The physical and mental demands of an elite football player are complex, which may explain why injuries are commonin football. At elite level, muscle injuries of the lower-extremity are the most common among male football players, and theresearch hitherto is limited. Objective: To investigate whether personality traits affect the incidence of muscle injuries amongmale football players from the first league in Sweden. Design: Prospective cohort study. Participants: A male football team fromthe first league in Sweden was prospectively followed, in terms of muscle injuries of the lower-extremity during 8 seasons,between 2007 and 2015. Intervention: All muscle injuries included in this study were evaluated and diagnosed withultrasonography. Players from the team filled out the Swedish Universities Scales of Personality questionnaire. SwedishUniversities Scales of Personality questionnaire consists of 91 items and is divided into 13 categories. Main Outcome Measures:The raw values of each scale were linearly transformed to T scores, having a mean (SD) of 50 (10). All variables weresummarized with standard descriptive statistics, such as frequency, mean, and SD. As data were of interval scale and no variabledistribution was severely skewed, differences between noninjured players, rarely injured players, and frequently injured playerswere analyzed with 1-way analysis of variance with post hoc tests by Tukey honestly significant difference test. Results:No significant difference in personality traits were observed between noninjured players, rarely injured players, and frequentlyinjured players regarding number of muscle injuries (P > .05). However, a trend (P = .07) was seen, where frequently injuredplayers scored higher on stress susceptibility than rarely injured players. Conclusion: A player’s stress susceptibility should betaken into consideration by the player, coaches, and medical staff when assessing the risk of a muscle injury. Also, preventivemeasures available for these players may need to be considered.