Chelsea are interested in deals to sign Ronald Araujo and Marc Cucurella, whilst the Blues have submitted an improved contract offer to Antonio Rudiger.
Chelsea’s defensive options ahead of next season are uncertain with a number of names out of contract at the end of the season, with the west Londoners considering a bid for Barcelona defender Araujo as the club look to strengthen at centre-back.
The 22-year-old has emerged as a key figure for the Spanish side this season, but has been frustrated in negotiations over a new deal at the Camp Nou.
Chelsea were strongly linked with Sevilla centre-back Jules Kounde last summer, and are said to retain an interest in the France international defender, while Leicester’s Wesley Fofana is also reported to be a potential target.
The European champions are also understood to be weighing up an approach for Brighton left-back Cucurella, who has impressed this season since his arrival from Getafe.
Chelsea had sought cover at left-back during the January transfer window, but were unable to find new additions and opted instead to recall Kenedy from his loan spell in Brazil.
The club’s interest in Cucurella is believed to hinge on whether Marcos Alonso leaves in search of more regular first-team football at the end of the season.
Elsewhere, Chelsea have increased their contract offer to Antonio Rudiger. The Blues had so far failed to match the centre-backs demands for a deal in the region of £200,000-a-week, but have sought a compromise as the club bid to keep the Germany international at Stamford Bridge.
With both Andreas Christensen and Cesar Azpilicueta also out of contract in the summer and considering exits, Chelsea want to ensure Rudiger remains despite interest from Real Madrid and Paris Saint-Germain.