Atletico Madrid have further expressed their desire to re-sign Diego Costa by submitting a formal offer with Chelsea.

According to The Sun, the Spanish club have bid £50million for the striker who is believed to be unhappy after two seasons at Stamford Bridge.

New Chelsea boss Antonio Conte said on Tuesday that he is eager to retain the services of 27-year-old Costa, despite signing Michy Batshuayi for £33m, and insisted that the player remains an important part of the Blues setup.

Diego Simeone is desperate to have the Brazilian-born Spain international back at the Vicente Calderon and instructed his club to make an offer, which has reportedly been turned down by Chelsea.

This rumour is unlikely to go away anytime soon especially seeing as the West Londoners continue to be linked with Real Madrid's Alvaro Morata, who returned to Spain this summer following a two-year stint at Juventus.