The aim of this study was to explore the perceived factors that contribute to stress and negative affective states during preseason among a sample of professional rugby union players. The participants were 12 male professional rugby union players between 18 and 21 years of age (M age = 19 years, SD = 0.85). Data were collected via semistructured interviews and analyzed using an inductive content analysis procedure. Players identified training (structure and volume), the number of matches played and the recovery period, diet, sleep, and travel as factors that they believed contributed to their experience of stress and negative affective states. The present findings suggest that players may require more time to recover between matches, alongside interventions to help players manage the symptoms of stress and negative affect during times in which players are overtraining.