Dembélé injured his left hamstring in the opening match of the 2019–20 La Liga season, a 0–1 defeat against Athletic Bilbao, and was expected to miss five weeks. In February 2020, he suffered a serious hamstring tear and, following surgery, was not expected to return for six months. This would mean despite the extension of the season due to the COVID-19 pandemic, he would miss the rest of the season.