Previous research has showed that psychosocial factors such as fatigue, could increase risk of injury (Borotikar et al., 2008; Johnson, 2011). Therefore, the aim of the study was to investigate the potential risk of different developmental trajectory profiles in fatigue, over three weeks, for injury among Swedish junior elite soccer players. Participants were 91 junior elite soccer players at the soccer high schools (64 male and 33 female) aged between 15-18 years (M =16.57, SD = .75). All players were asked, at a weekly basis during the first three weeks of pre-season, to complete the fatigue sub-scale from Recovery-Stress Questionnaire for Athletes-Sport (Kellman & Kallus, 2001). Two months after, the athletic trainers of the participants were asked to record any injury that occurred in the last two months. Latent class analysis was performed to analyze the data. Sample adjusted BIC was used to evaluate the goodness-of-fit and to help select the best fitted model (Yang, 1998). Relative risk ratios were calculated to compare the injury risk between participants in various latent classes identified from the latent class analysis. The model with best fit (BIC = 832, entropy .77) contained four different latent classes (i.e., low stable, moderate stable, high increasing, high decreasing). Members of the low stable class characterized by low levels of fatigue over the three-week period (Intercept = 2.5, slope = -.16) were selected as the reference class when calculating relative risk rations. Members of the high increasing class, experiencing high and increasing level of fatigue over the three-week period (Intercept = 4.94, slope = .29), were exposed to the highest risk of injury (RR = 2.53), compared with the reference class, and with other classes. Results from the participants included in the two other classes as (1) the moderate stable, characterized by a stable moderate level of fatigue during the course of assessment (Intercept = 3.78, slope = .14), and (2) the high decreasing, with high but decreasing level of fatigue during the three-week period (Intercept= 5.97, slope = -1.14), were both exposed to a 1.63 greater risk of injury than the reference class. The result indicates that high levels of fatigue might increase the risks of injury among soccer players. In other words, players’ risk in sport might potentially be reduced by proper recovery protocols. It is therefore highly recommended that coaches and medical staff should work actively and continuously with athletes to aid their physical and psychological recovery.