The Blues are expected to bring a new left-sided full-back to Stamford Bridge this summer, with Marcos Alonso and Emerson Palmieri expected to leave ahead of the 2020-21 campaign.
Leicester City’s Ben Chilwell has been strongly linked with a move, but the Foxes appear to be pricing the England international out of a summer exit.
According to Mundo Deportivo, Chelsea have now launched a €25m (£23m) bid for Tagliafico as they prepare to battle the likes of Atletico Madrid and Manchester City for his signature.
The 27-year-old recently suggested that he would be on the move ahead of the 2020-21 campaign, leading to a host of speculation surrounding his future.
The Argentina international enjoyed an impressive 2019-20 campaign for his Dutch club, scoring five times and contributing seven assists in 38 appearances in all competitions.