Chelsea was previously linked to the 24-year-old goalkeeper last summer. Enzo Maresca, a former coach of Hermansen, had recommended him to the club's management.
Chelsea's interest in Hermansen may be reignited due to the sale of Kepa Arrizabalaga to Arsenal. The West London club currently has six goalkeepers, but they are looking to reduce the number by either selling or loaning them out this summer.
West Ham United is also interested in Hermansen, but Chelsea's offer might be difficult for him to decline.