Owner Roman Abramovich will back Jose Mourinho in the transfer market this summer, with a midfielder, defender, forward and keeper on their wish-list.
Atletico Madrid winger Antoine Griezmann, Lyon forward Alexandre Lacazette, Real Madrid defender Raphael Varane and Getafe keeper Vicente Guaita are on their radar given their amazing performances so far this season for their respective clubs in their respective leagues.
Keeper Petr Cech, 32, will be allowed to leave, Brazilian midfielder Oscar may also be sold and full-back Filipe Luis could go back to Atletico Madrid after just one season with the Blues as replacments for France international Griezmann, who has a £45m buy-out clause in his contract.
Chelsea are also watching developments on Gareth Bale at Real Madrid and are interested in Barcelona wideman Pedro, who will be allowed to leave Barcelona this summer.
The new Premier League champions plan to step up negotiations over giving manager Jose Mourinho two more years on his £12million-a-year deal, tying him down until 2019.
Greizmann has scored 25 goals in 51 apperances in all compeititons, Lacazette 31 in 38 apperances, while Varane has been spectular for Real Madrid as the center back and great performences from Guaita in goal for the Spanish club.