Spanish daily sports newspaper Diario AS have reported that Chelsea want to extend and improve Diego Costa's contract in light of interest from former club Atletico Madrid.
The 28-year-old Brazilian-born Spain international has been in scintillating form for the Blues this season, scoring nine goals in 13 appearances in all competitions.
And Antonio Conte - who took charge of Chelsea this summer - is said to be intent on keeping one of his prized assets and warning off Diego Simeone's Atleti.
AS' story is headlined, 'Blindaje Anti Atleti Para Diego Costa' meaning, 'Anti-Atleti Protection For Diego Costa' in Spanish.