Chelsea have approached Atletico Madrid to ask about midfielder Saul Niguez, according to reports in Spain.
The transfer window officially opens on June 9 and speculation is well underway with names being linked with a move to the Champions League winners this summer.
It will be Thomas Tuchel's first full window in charge of the Blues and he is set to be backed by Roman Abramovich.
And reports out of Spain and Mundo Deportivo, as relayed by Sport Witness, claim Chelsea have 'already asked' about Saul's availability this summer.
Chelsea, Paris Saint-Germain, Bayern Munich and Juventus are all reportedly interested in the Spaniard who is 'determined' to leave this summer and Atletico would reportedly 'welcome' a sale
The 26-year-old is valued at €80 million by Atletico which could put off prospective buyers considering the midfielder wants to leave this summer.
Saul only started 22 times for Atletico in their title-winning La Liga campaign this term, and Chelsea are believed to be in the market for a midfielder. Declan Rice has been strongly linked with a switch to west London.
It has been suggested that Tuchel wants four players this summer to bolster his Chelsea squad, with many exits expected at Stamford Bridge this summer. Seven players have already been confirmed to be departing at the end of their contracts this month.