Acute lower back pain in a fit healthy male with recent strenuous physical activity is often attributed to muscle strain. We report a rare case of erector spinae pyomyositis developing in a young and otherwise healthy young adult male that was almost misdiagnosed as muscle strain. Despite admission and close monitoring, diagnosis was only confirmed on a magnetic resonance imaging of the spine later during the hospital stay. Early diagnosis in this case allowed successful treatment with intravenous antibiotics alone, without requiring further surgical drainage or development of further neurological sequelae, common in later stages of erector spinae pyomyositis.