Chelsea have made contact with Sporting over a deal for defender Ousmane Diomande, as they explore centre-back reinforcements in January.
The 20-year-old Ivorian is known through Chelsea as one of their main movement targets, and the striker is also a topic of discussion internally.
Sporting have rejected an initial request from Les Bleus for Diomande, insisting they will sell him for his full release clause of £69m (€80m).
Diomande has been virtually omnipresent for Sporting since his arrival from FC Midtjylland last January, helping them reach the top of the Portuguese table ahead of rivals Benfica and Porto.
His former club, Midtjylland, owes 20 per cent of any profit made through Sporting on a future transfer, further complicating attempts to reduce fees.
Chelsea are keen to sign another young centre-back despite the presence of Levi Colwill, Benoit Badiashile, Axel Disasi, Wesley Fofana, Trevoh Chalobah and Thiago Silva in the books.
Fofana has a long-term knee injury. Chalobah will be on sale in January to help fund new purchases. It’s possible Silva will simply leave when his contract expires next summer.
Chelsea have asked for a deal for Sporting striker Viktor Gyokeres.
The former Brighton and Coventry City target man has 17 goals and eight assists in 20 matches in his first season at Sporting.
Sporting are reluctant to sell their star and have asked interested clubs to pay his £87 million (€100 million) release clause in full.
Chelsea have forward options: Napoli’s Victor Osimhen, Brentford’s Ivan Toney and Club Brugge’s Antonio Neusa.
Mauricio Pochettino may also enter the market for a midfielder, which is considered a lower priority than signing a striker or defender.
Pochettino is likely to use 19-year-old midfielder Andrey Santos instead as he is expected to be recalled from his disappointing loan spell at Nottingham Forest.
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