The Red Devils are ready to smash the British transfer record to secure the Uruguayans services.
Romelu Lukaku will leave Chelsea and replace Diego Costa at Atletico Madrid.
Lorenzo Insigne will stay at Napoli according to his agent.
Chelsea are hoping to sell Marko Marin back to his former club Werder Bremen to make way for new signing Cesc Fabregas.
Marin, who spent last season on-loan at Spanish club Sevilla, is available for only £7m.
Negotiations are already underway over a deal that will see Marin return to Germany after two unsuccessful years at Chelsea.