There is little research examining how individuals’ daily experience during a pandemic affects their daily mental health status and work performance. To address this knowledge gap, we invoke conservation of resources theory to propose a resource-based framework explaining how individuals’ daily COVID-19 intrusive experience affects their daily mental health status (depression and anxiety) and work performance via its effect on daily psychosocial resource loss and gain; We further examine whether their supervisors’ daily visionary leadership behaviour alleviates the adverse impacts of daily COVID-19 intrusive experience. Results, based on daily diary data from 139 football players (or soccer players) at 15 professional football clubs over 5 days during the COVID-19 pandemic, provided support for our predictions. Our study extends the literature by providing previously undocumented evidence on daily within-person variations in mental health status and work performance during a pandemic and by offering theory-driven insights into the mediating and moderating mechanisms involved in within-person variations.