The aims of this study were: (a) to explore the relationships between adaptive defense mechanisms (ADMs), maladaptive defense mechanisms (MADMs), stress, recovery, resilience, and sport burnout; and (b) to examine resilience, stress, and recovery as mediators of the relationship between defense mechanisms and burnout. One hundred and seventy-five athletes (M = 20.30 years, SD = 3.75) completed self-report questionnaires assessing defense mechanisms, resilience, stress, and recovery. Correlation analysis revealed that MADMs were positively associated with burnout, while ADMs had no significant link with burnout. Concerning mediation analysis, results showed a mediating effect of resilience in the relationship between ADMs and burnout. The findings also demonstrated a mediating effect of resilience and recovery in the relationship between MADMs and burnout. Our study highlighted that certain defenses categorized as adaptive might not be suitable in specific situations, thus underscoring the influence of mediating variables. The findings of mediation analysis demonstrated that resilience appears to serve as a particularly protective factor against burnout. On the contrary, MADMs would have a deleterious influence in the management of stress, which could lead to burnout. Coaches may consider fostering athletes' resilience in conjunction with ADMs and implementing targeted psychological exercises to reduce the use of MADMs.